Observing the sky with photons, cosmic rays, and gravitational waves, is giving us an ever deeper understanding of the universe we live in. In this talk, I trace my personal journey from searching for magnetic monopoles to observing neutrino oscillation, and finally, to discovering gravitational waves.
Atmospheric neutrinos have been crucial in advancing our knowledge of neutrino oscillations. Notably, this source of neutrinos provided one of the first evidences of this phenomenon in the late 20th century. Since then, significant progress has been made, bringing us closer to the so-called precision era of neutrino oscillation physics. SuperK has demonstrated for over three decades that...
The CALorimetric Electron Telescope (CALET) is a space-based experiment performing direct cosmic-ray observations aboard the International Space Station. Since the start of observations in October 2015, CALET has been continuously collecting scientific data for more than nine years. The instrument is capable of measuring individual cosmic-ray nuclei, covering a wide energy range from a few...
The installation of two new neutron monitors, HLEA and THIMON, at the summit of Haleakalā, Hawai‘i, marks a significant advancement in cosmic ray and solar neutron studies. Situated at 3,055 meters above sea level, these monitors benefit from minimal atmospheric interference, enabling high-precision measurements of galactic cosmic rays (GCRs) and solar neutron flux. Operational since December...
The FASER experiment at the LHC aims to study neutrinos of all three flavors at TeV energies and search for new long-lived particles. The FASER detector, a 1-ton-scale emulsion-electronic hybrid neutrino detector, is located 480 m downstream of the ATLAS $p$-$p$ interaction point, directly in the line of sight. Data taking began with the start of LHC Run 3 in 2022, and a total of 190 fb$^{-1}$...
: The extragalactic background light (EBL) contains all the radiation emitted by nuclear and accretion processes in stars and compact objects since the epoch of recombination. Measuring the EBL density directly is challenging However, gamma-ray astronomy provides an alternative approach to indirectly studying the EBL through the observation of gamma-ray absorption in the spectra of distant...
Galactic Cosmic Rays (GCR) are a common background for measurements of solar activity. Measurements of long-lived isotopes in meteoritic data indicate the GCR flux has been constant for several Myr, but these measurements have relative systematic uncertainties exceeding 30%. By using deep-ice carbon-14 extracted from the Antarctic ice sheet at Dome C, we can reconstruct changes in the GCR...
The Andes Large area PArticle detector for Cosmic ray physics and Astronomy (ALPACA) is a new air shower array experiment under construction in the Bolivian Andes at the altitude of 4740m. The aim of the experiment is to explore the southern gamma-ray sky beyond 100 TeV to reveal the yet unknown PeV cosmic-ray accelerators. The surface array consisting of 401 plastic scintillating counters...
The leader fraction, L, is defined as the fraction of neutron monitor counts that are not temporally associated with a later count in the same neutron monitor counter due to the same cosmic ray shower. L was extracted from time-delay histograms and serves as a precise indicator of spectral variations in cosmic rays above the cutoff rigidity. In this work, we analyze long-term variations in L...
The intrinsic gamma-ray flux from extragalactic sources in the very-high-energy (VHE; E>100GeV) regime is subject to attenuation due to interactions with photons of the extragalactic background light (EBL), leading to pair production. Consequently, the Universe is expected to appear opaque to VHE photons above certain energy thresholds, depending on the redshift of the source. An oscillation...
The DArk Matter Particle Explorer (DAMPE) is a space based detector operating since its launch in December 2015. The primary goals of the mission include the measurement of the cosmic e+e − spectrum, the high energy gamma-ray astronomy, and the analysis of the flux and composition of cosmic ray protons and nuclei from tens GeV up to several hundreds TeV.
This study presents a direct...
High-energy collisions at the Large Hadron Collider (LHC) have traditionally focused on particle production at small pseudorapidities. However, to further utilize the valuable data from particles produced at the ATLAS interaction point along the beamline, the proposed Forward Physics Facility (FPF) aims to study particle production in the far-forward region at the high-luminosity LHC. The FPF...
The GELATICA experiment (GEorgian Large-area Angle and TIme Coincidence Array) comprises several cosmic ray detector arrays located in two cities in Georgia. These observatories are designed to detect Extensive Air Showers (EAS) with high-precision timing and determine the arrival directions of cosmic ray showers. GELATICA is part of the CREDO collaboration (Cosmic Ray Extremely Distributed...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a next-generation experiment and offers precise wide-field observations of the southern gamma-ray sky. SWGO will be located in Pamba la Bola, Chile, at an altitude of 4770 m, cover an area of 1 km² and complement CTA and LHAASO. By leveraging double-layered Water Cherenkov Detectors, the SWGO design will facilitate gamma-ray observations...
The history of photon production and galaxy evolution since the epoch of reionization is encoded in the extragalactic background light (EBL). Above an energy threshold, $\gamma$-rays can interact with the optical and infrared photons that dominate the EBL, resulting in an absorption imprint in the spectra of extragalactic sources. The combined observations of the current generation of...
Solar storms can disturb Galactic cosmic-ray (GCR) fluxes within the heliosphere at short time scales in events known as Forbush decreases (FDs). We extract hourly GCR spectral variations during FDs from a global network of ground-based neutron monitors and muon detectors using two independent methods: A) fitting a GCR rigidity spectral model with anisotropy up to second order, and B)...
Recently, LHAASO has performed precise measurements of the all-particle spectrum and the mean logarithmic mass $\langle \ln A \rangle$ of cosmic rays at energies around the knee (~4 PeV). These data provides an unprecedented opportunity to test models of Galactic CR acceleration and propagation, bridging direct and indirect measurements for the first time. In this work, we develop a...
If neutrinos were the one (and only) instance of elementary particles of the Majorana type, they could undergo a hypothetical process violating lepton number, the so-called neutrino-less double-beta decay (0νββ). If 0νββ indeed were observed, that would be enough to claim the Majorana nature of neutrinos. This would have substantial repercussions on cosmology and provide a possible mechanism...
The SWGO collaboration proposes constructing a wide-field-of-view observatory to explore the southern hemisphere sky in the 100 GeV - 1 PeV energy range. The selected site is the Atacama Astronomical Park in Chile. Currently, the HAWC and LHAASO experiments are the only ground-based arrays for gamma-ray detection operating in this energy range, and both are located in the northern hemisphere....
The diffuse gamma-ray background (DGRB) measured by various telescopes spans over a wide energy range from keV to around TeV. In the energy range (100 MeV-820 GeV), the DGRB can be explained by sources such as blazars and star forming galaxies. Whereas in the lower energies up to around 0.3 MeV, the dominant sources are found to be active galactic nuclei and Seyfert galaxies. However, in the...
The Calorimetric Electron Telescope (CALET) is carrying out direct measurements of the main components of high energy cosmic rays up to ~1 PeV in order to obtain systematic understanding of cosmic ray acceleration and propagation. The detector consisting of a charge detector, an imaging calorimeter, and a total absorption calorimeter, is located on the International Space Station. The...
The Jiangmen Underground Neutrino Observatory (JUNO) is a next-generation neutrino experiment located in China, currently undergoing the Liquid Scintillator (LS) filling phase. With 20 ktons of ultra-pure LS, JUNO seeks to make world leading measurements of three neutrino oscillation parameters and determining the Neutrino Mass Ordering (NMO).
Even though it is designed to primarily use...
The Sun can occasionally accelerate particles to become solar energetic particles, some of which may collide with the Earth’s atmosphere and produce secondary air showers that ground-based neutron monitors can detect. This work investigates the Princess Sirindhorn Neutron Monitor (PSNM) response to solar neutrons originating from solar activity such as solar flares and coronal mass ejections....
Protons are the most abundant component of Cosmic Rays (CRs), predominantly of primary origin. Due to their relatively high flux compared to the other CR elements, they constitute a unique footprint of the high-energy CR phenomena that can be probed with space experiments. Recent results of the DAMPE mission on the combined proton plus helium flux indicate the presence of a new structure – a...
Paleo-detectors offer a unique opportunity to probe the long-term history of cosmic ray-flux, potentially revealing evidence of nearby supernovae and other high-energy astrophysical events. This technique relies on the persistent damage tracks left in natural minerals by nuclear recoils induced by cosmic ray secondaries, providing an integrated record of particle flux over geological...
The forthcoming Southern Wide-field Gamma-ray Observatory will be located in Chile and ideally situated to observe the southern Galactic Plane. With its continuous survey capabilities and large collection area at high energies ≥ 100 TeV, SWGO will significantly contribute to studies of galactic gamma-ray sources. In this contribution, we refine the galactic science case for SWGO in light of...
In order to develop a consistent quantum theory of gravity, we must understand whether spacetime exhibits fluctuations at the Planck scale. If these Planck-scale fluctuations exist, they may cause propagating particles to evolve in an apparently non-unitary manner. Neutrinos, which interact only via the weak force and gravity, maintain quantum coherence while propagating over large distances....
The Askaryan Radio Array (ARA) is an in-ice ultra-high-energy (UHE, >10 PeV) neutrino experiment at the South Pole, designed to detect neutrino-induced radio emission in ice. It consists of five independent stations, each featuring a cubic lattice of in-ice antenna clusters spaced ~30 m apart and buried ~200 m below the surface. The fifth ARA station (A5) is unique due to its central phased...
The Southern Wide-field Gamma-ray Observatory (SWGO) will be a next generation ground array experiment probing the Southern sky in search of gamma-ray sources from the Galactic plane. The experiment will be located in the Atacama Astronomical Park at 4770 m above sea level. The observatory will be a wide field of view and high duty cycle (almost 100%) array measuring the Extensive Air Showers...
A latitude survey using the Changvan neutron monitor, a ship-borne detector, was conducted aboard the South Korean Icebreaker "Araon" in 2023–24, spanning from Antarctic and Arctic regions to study cosmic ray modulation. The monitor features a 3NM64-like configuration with three proportional counters: a leaded BF₃ tube from LND Inc. at one edge, an unleaded BP28 tube in the middle, and a...
The InterGalactic Magnetic Field (IGMF) is believed to be a remnant of the Big Bang and the origin of cosmological magnetic fields. However, it has yet to be detected. The Cherenkov Telescope Array Observatory (CTAO) will have the potential to place stricter constraints on the IGMF by analysing data from AGN and GRBs. In this study, we propose to simulate realistic observations in CTAO of GRBs...
The ALPACA experiment, which consists of the large air shower array (83,000 m^2) and the water-Cherenkov-type muon detector (3,600 m^2), is a new project to observe cosmic rays and gamma rays in the energy range between TeV and PeV in the southern hemisphere. The prototype air shower array, named ALPAQUITA (18,000 m^2), has been fully operated at the Chacaltaya plateau (4,740 m a.s.l.) in...
The ASTRI Mini–Array is an international project led by INAF to install and operate nine innovative Imaging Atmospheric Cherenkov Telescopes (IACTs) at the Observatorio del Teide site e, resulting from a hosting agreement between INAF and IAC. The facility will operate for at least 8 years. It will deeply observe the Galactic and extra-galactic sky at TeV energies to study compelling open...
The CALorimetric Electron Telescope (CALET) is a space-based calorimetric
instrument, designed to carry out precise measurements of high energy cosmic rays. Installed on the Japanese Experiment Module – Exposed Facility on the ISS, it is collecting data with excellent performance and no significant interruptions since October 2015. We present the updated results of the direct measurement of...
The Moon-Aiming Thai-Chinese Hodoscope (MATCH) is designed as a space weather payload for the Chang’E-7 lunar orbiter, aimed at enhancing space weather monitoring in the Earth-Moon region and measuring lunar albedo ions up to approximately 100 MeV/n. Additionally, it will provide continuous measurements of cosmic ray electrons up to around 120 MeV/n, thereby clarifying the contributions from...
The IceCube Neutrino Observatory recently published evidence for diffuse neutrino emission from the Galactic Plane at $4.5\sigma$ significance. This new source of astrophysical neutrinos provides an exciting laboratory for probing the nature of neutrino masses. In particular, extremely small mass splittings, such as those predicted by quasi-Dirac neutrino mass models, and finite neutrino...
The origin of magnetic fields on cosmological scales remains one of the longstanding problems in cosmology. Magnetic fields observed in galaxies and clusters are typically explained through the amplification of weak seed fields. However, the nature of these weak seed fields remains largely unknown. Two scenarios are usually considered: the cosmological and the astrophysical scenarios.
To...
We report the latest results of primary cosmic ray proton, helium, carbon, oxygen, neon, magnesium, silicon, sulfur, and iron fluxes based on the data collected by the Alpha Magnetic Spectrometer experiment on the International Space Station during 13.5 years of operation. The unique properties of primary cosmic rays will be discussed.
The anisotropy in different mass components of cosmic rays can provide stringent constraints on theoretical models regarding the origin of anisotropy, such as the distribution of sources, the propagation of cosmic rays, and the local magnetic field environment. This is particularly significant in the high-energy range, from hundreds of TeV to PeV, where the anisotropy exhibits considerable...
We present preliminary results on an updated full-sky analysis of the cosmic-ray arrival direction distribution with data collected by the High-Altitude Water Cherenkov (HAWC) Observatory and IceCube Neutrino Observatory with complementary field of views covering a large fraction of the sky. This study extends the energy range to higher energies. The HAWC Observatory, located at 19°N has...
LunPAN (Lunar Particle Analyzer Network) is a three-year mission proposal designed to comprehensively map the particle spectra in the lunar radiation field. It aims to provide precise measurements of Galactic Cosmic Rays (GCR), Solar Energetic Particles (SEP), and albedo particles, including charged particles, neutrons, and gamma-rays, originating from the Moon's surface. Therefore it will...
Intergalactic weak magnetic fields can have non-negligible effects on the electromagnetic cascades induced by blazar gamma-ray emission. Secondary electrons and positrons are produced by primary gamma rays of energies ~TeV and can be magnetically deflected out of the line of sight to the source. However, these leptons can perturb the background intergalactic medium (IGM), resulting in the...
The Dark Matter Particle Explorer (DAMPE), is a space–borne detector designed for precise Galactic Cosmic Ray (GCR) studies in a wide energy range (up to a few hundreds of TeV), along with detailed measurements of high–energy gamma–rays and indirect searches of Dark Matter (DM). The satellite was successfully launched into a sun–synchronous orbit at 500 km, on December 17th 2015 and has been...
The ASTRI Mini-Array is an international project to build and operate an array of nine 4-m diameter Imaging Atmospheric Cherenkov Telescopes (IACT) at the Observatorio del Teide (Tenerife, Spain). The array has been designed to perform deep galactic and extragalactic gamma-ray sky observations in the 1-200 TeV energy range. As of today, the first telescope ASTRI-1 is fully operative, and in...
Identification of primary cosmic rays on an event-by-event basis is a much-desired capability of cosmic-ray observatories. Several cosmic-ray air-shower experiments use so-called photon tags for gamma/hadron primary particle discrimination. These photon tag variables are derived from the total signals measured by an array of detectors and are correlated with the total number of muons in the...
We present the measurement of the individual energy spectra for boron, carbon, nitrogen and oxygen cosmic rays based on data collected by the CALorimetric Electron Telescope (CALET) during more than 9 years of operation on the International Space Station. These spectra are measured in the energy range from 10 GeV/n to several TeV/n using a fully calorimetric instrument, 1.3 nuclear interaction...
TSC-1 is the first Thai scientific research mission on a microsatellite, which has been designed and developed by the Thai Space Consortium. The satellite is planned to operate in Sun-synchronous Earth orbit at 500 - 600 km altitude and should be launch ready at the end of 2026. All design, construction, system integration, and testing are to be carried out in Thailand. The payloads include...
The Large High Altitude Air Shower Observatory (LHAASO) has recently detected over 40 ultra-high-energy (UHE) gamma-ray sources. However, many of these sources are extended, and some are located within a small angular region (~1°) that LHAASO cannot resolve clearly. To address these limitations, the Large Array of Imaging Atmospheric Cherenkov Telescopes (LACT) has been proposed and is...
The interaction of cosmic rays with celestial bodies such as the Moon or the Sun produces a shadow in the arrival direction distribution of the cosmic rays reaching the Earth. Such deficits from an isotropic flux have been observed by astroparticle observatories below energies of $10^{15}\,$eV. Above this energy, measurements were limited due to the low number of events as a result of the...
The China Seismo-Electromagnetic Satellite (CSES) program, a collaboration between the China National Space Administration (CNSA) and the Italian Space Agency (ASI), offers a new window into solar-terrestrial interactions through continuous monitoring of the near-Earth space environment. Since its launch in 2018, CSES-01 has provided valuable data on space weather phenomena, ionospheric...
The Dark Matter Particle Explorer (DAMPE) is a satellite-based detector optimized for precise Galactic cosmic ray studies up to hundreds of TeV. Since its launch on December 17th, 2015, DAMPE has been continuously collecting data on high-energy cosmic particles with excellent statistics and particle identification capabilities, thanks to a large geometric factor and a very good energy...
Large Array of imaging atmospheric Cherenkov Telescope (LACT) is an array of 32 Cherenkov telescopes with 6-meter diameter mirrors to be constructed at the LHAASO site, aiming to enhance our understanding of ultra-high energy gamma ray astronomy. This work presents a detailed performance assessment of the LACT array, focusing on the IRFs for both an 8-telescope subarray configuration optimized...
Unveiling the sources of ultra-high energy cosmic rays remains one of the main challenges of high-energy astrophysics. Measurements of anisotropies in their arrival directions are key to identifying their sources, yet magnetic deflections obscure direct associations. In this work, we reconstruct the sky regions of origin of the highest-energy cosmic-ray events detected by the Pierre Auger...
The intensity of Galactic cosmic rays in the arrival directions is highly isotropic, however, many cosmic ray experiments have observed weak anisotropies of various angular sizes. In this work, we report the observation of the medium-scale structures with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO-KM2A). We have found that the positions of the excess...
We report the latest results on the properties of Cl and K cosmic rays fluxes in the rigidity range 2.5 GV to 1.3 TV based on 0.14 million Cl and 0.17 million K nuclei collected by the AMS. We observe that fluxes are well described by the sums of a primary cosmic ray component and a secondary cosmic ray component. With our measurements, the abundance ratios at the source Cl/Si and K/Si are...
Astrophysical flares are one of the possible prominent source classes of ultra-high-energy (UHE, E > 10^17 eV) cosmic rays, which can be detected by recording clusters of extensive air showers in arrays of detectors. The search for sources of neutral particles offers distinct advantages over searching for sources of charged particles, as the former traverse cosmic distances undeflected by...
The CALorimetric Electron Telescope (CALET) is a high-energy astroparticle physics experiment in operation on the International Space Station (ISS) since 2015 with excellent and continuous performance. Designed to measure the spectra of electrons+positrons up to 20 TeV (and gamma rays up to 10 TeV), CALET is searching for possible nearby sources of high-energy electrons and dark matter...
The CALorimetric Electron Telescope (CALET) installed on the International Space Station (ISS) has been measuring high-energy cosmic rays (CRs) and gamma rays to understand the cosmic-ray acceleration and propagation. The CALET adopts a low-energy electron (LEE) trigger working at high geomagnetic latitudes that can measure the low-energy CR electrons in the energy region from 1 GeV to 10 GeV,...
Terrestrial Gamma-ray Flashes (TGFs) are intense bursts of gamma rays originating in Earth's atmosphere, often associated with lightning activity during thunderstorms. These flashes are believed to result from relativistic runaway electron avalanches triggered by strong electric fields. In this study, we analyze multiple TGFs observed at the Telescope Array Surface Detectors site using a suite...
We present high statistics measurements of the secondary cosmic rays Lithium, Beryllium, Boron, and Fluorine. The properties of the secondary cosmic ray fluxes and their ratios to the primary cosmic rays Li/C, Be/C, B/C, Li/O, Be/O, B/O, and F/Si , are presented. The comparison with the latest theoretical models is also presented.
The large high altitude air shower observatory has comprehensively measured the information of the air showers of very high energy cosmic rays. Several important results regarding the air shower already have been published. A cosmic ray mass independent energy reconstruction method has been proposed by combining the muon content and the electromagnetic particles (or Cherenkov light) of the air...
The Antarctic Demonstrator for the Advanced Particle-astrophysics Telescope (ADAPT) is a NASA suborbital mission scheduled for a high-altitude balloon flight over Antarctica during the 2025-2026 season. ADAPT aims at validating key detector technologies for the forthcoming space-based Advanced Particle-astrophysics Telescope (APT) mission, an MeV-TeV gamma-ray telescope designed to provide an...
The astrophysical community is currently focusing on the development of next-generation gamma-ray telescopes designed to detect low-energy photons in the MeV-GeV range, operating in both the Compton and pair conversion regimes. The proposed Advanced Particle-astrophysics Telescope (APT) is a planned space-based, MeV-TeV gamma-ray mission aimed at providing an order of magnitude improvement in...
Extremely high-peaked BL Lac objects (or extreme blazars) are unique extragalactic laboratories where particle acceleration processes are pushed at their physical limits. In these blazars, synchrotron emission peaking above keV energies is reprocessed to very-high-energy (VHE, energies > 100 GeV) gamma rays, often resulting in very hard TeV spectra. Over the past two decades, they have...
The muon puzzle, the excess of the number of muons with respect to simulations in ultra-high energy cosmic rays, was initially reported by the Pierre Auger Observatory in 2015 and confirmed by more recent analyses. This suggests that forward meson production in hadronic interactions is not fully understood. Most scenarios to solve this issue predict less production of forward neutral pions and...
The precise measurement of secondary cosmic ray (CR) fluxes provides crucial insights into the propagation and interaction of high-energy particles in the Galaxy. Primary CRs—such as carbon and oxygen nuclei—are believed to interact with the interstellar medium (ISM) and fragment into lighter secondary CRs. Boron is one of the most abundant elements among secondary CRs and its spectrum serves...
The precision measurement of the daily proton and helium fluxes with AMS during 13.5 years of operation will be presented. The period of observation covers solar cycle 24 from the ascending phase through its maximum going toward its minimum and solar cycle 25 through solar maximum. Detailed time variations of fluxes and ratio, including periodicities, will be presented. Remarkably, a...
The network of two next-generation underwater Cherenkov neutrino telescopes: ARCA and ORCA is being successively deployed in the Mediterranean Sea by the KM3NeT Collaboration. The focus of ARCA is neutrino astronomy, while ORCA is mainly dedicated to neutrino oscillation studies. Both detectors are already operational in their intermediate states and collect valuable results. This work...
DAMPE (DArk Matter Particle Explorer) is a space-based particle detector launched in December 2015 to observe high-energy electrons, gamma rays, and cosmic rays. Secondary cosmic ray fluxes serve as key probes of the propagation and interaction of high-energy particles in the Galaxy. Spectral measurements of secondary nuclei, such as lithium, beryllium, as well as their ratios to primary...
Gamma-Ray Bursts (GRBs) are among the most energetic events in the Universe. Despite over 50 years of research and measurements their prompt emission remains poorly understood, with key questions surrounding the structure of relativistic jets, magnetic field configurations, and dominant radiation mechanisms. Polarization measurements are critical in resolving these uncertainties. The POLAR...
Since 2014, the Pierre Auger Observatory has exploited a dedicated trigger, and its very high time resolution to do studies on ELVES and harvest record samples of multiple ELVES using the Fluorescence Detector (FD). In 2017, after extending the readout of trace lengths to 0.9 ms, we started observing other types of light transients from the base of the ionosphere, such as HALOS, which...
Precise knowledge of high energy hadronic interaction is an important key to understand air shower development. The LHCf experiment measures neutral particles such as photons, neutral pions, and neutrons, produced in the very forward region of LHC collisions, which contribute to the air shower development. Since the LHC start, LHCf performed many operations with pp collisions at several...
Atmospheric neutrinos (ATNs) are widely studied in the context of neutrino oscillation parameter measurements due to a wide range of propagation baselines and neutrino energies. Determining parameters such as $\theta_{23}$ and $\Delta m_{32}^2$ relies on precise experimental measurements of the atmospheric neutrino flux. The theoretical prediction of ATN flux significantly influences the...
Changing-look (transitional) blazars shift between subclasses at different flux states. It is, therefore, crucial to study them to comprehend the fundamental physics governing blazars and the relationships between their different subclasses. VERITAS has detected very-high-energy (VHE; E>100 GeV) emissions from several transitional blazars during flaring states, revealing their capability of...
The atmospheric muon flux has been measured by several experiments mainly between the 60s and 80s of the last century. Nonetheless the study of these particles is still of interest at least in two different fields of physics research. The first one is related to neutrino physics. A precise measurement of the parameters that characterize the phenomenon of oscillation between the three...
The connection between cosmic ray air showers and thunderclouds has become a major research topic in recent years in high-energy atmospheric physics.
One of the open questions is whether cosmic rays are involved in triggering a “gamma-ray glow”. A “gamma-ray glow” is a phenomenon in which gamma-ray increases for tens of seconds to several minutes during the passage of thunderclouds. A strong...
The steady-state gamma-ray emission from the Sun arises from interactions with Galactic cosmic rays and consists of two components: (1) a hadronic disk component and (2) a leptonic component peaking at the solar edge and extending into the heliosphere. Their flux is expected to vary with the 11-year solar cycle, peaking at solar minimum due to the higher cosmic-ray flux. However, no previous...
WINK is a proof of concept prototype designed to test, enhance and approve the base technology of Crystal Eye. While Crystal Eye is intended for all-sky monitoring of X and gamma rays in the 0.1–30 MeV range, whose primary objectives include investigating the prompt emissions of Gamma Ray Bursts (GRBs) - and acting as pointing system for other detectors in order to study the associated...
We present a new approach to modeling cosmic ray (CR) interactions, which relies on a very basic interaction picture, while using a reasonable and transparent formalism, in the framework of the Reggeon Field Theory. Our main motivation is to provide a new CR interaction model characterized by relatively transparent physics, sufficient parameter flexibility, and high computational efficiency,...
The last generation of Galactic cosmic-ray experiments is providing a wealth of high-precision new data. The interpretation of these data is stimulating a very rich and active debate in the community, with strong discovery and constraining potentials on many topics (dark matter, acceleration and transport of cosmic rays, Galactic sources etc.). However, the consensus in the community is that...
The DArk Matter Particle Explorer (DAMPE) is a spaceborne high-energy particle detector launched on December 17, 2015, as part of an international collaboration led by the Chinese Academy of Sciences. DAMPE is designed to investigate cosmic-ray electrons and γ-rays with unprecedented energy resolution and sensitivity. By operating in low Earth orbit at an altitude of approximately 500 km,...
During its first phase, from 2004 up to the end of 2012, the H.E.S.S. (High Energy Stereoscopic System) experiment observed the extragalactic skies for more than 2700 hours. These data have been re-analysed in a single consistent framework, leading to the derivation of a catalog of 23 sources. In total, about 6.5% of the sky was observed, allowing for several additional studies to be...
The development of advanced space-based cosmic ray observation experiments (such as AMS, PAMELA, and DAMPE) have provided precise data, offering new opportunities for the study of cosmic ray solar modulation. During 2007-2008, as the period of longest-live coronal holes and corresponding variation in all heliospheric characteristics, the pronounced 27-day wave in the GCR intensity had been...
DR-TES (Dilution Refrigerator - Transition Edge Sensors) is a balloon-borne experiment aimed at demonstrating advanced cryogenic and detector technologies for X-ray and gamma-ray spectroscopy in a near-space environment. The mission utilizes a low-temperature TES detector array, cooled to ~75 mK by a miniature dilution refrigerator (mini-DR), which itself is pre-cooled by a liquid helium...
Accurate measurements of cosmic-ray fragmentation cross sections are essential for maximizing the physics potential of precise measurements of secondary and primary cosmic-ray fluxes from current balloon and spaceborne experiments. NA61/SHINE, operating at the CERN SPS H2 beamline, is uniquely suited for studying these interactions at high energies above 10 GeV/nucleon.
In this...
Measuring proton-proton interaction cross-sections at center-of-mass energies above 40 TeV remains a significant challenge in particle physics. The Pierre Auger Observatory provides a unique opportunity to study the interactions at the highest energies through the distribution of the depth of maximum shower development ($X_\mathrm{max}$) observed by its Fluorescence Detector. In previous...
Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron ($D$) flux are presented. The measurements are based on 21 million $D$ nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021. We observe that over the entire rigidity range the $D$ flux exhibits nearly identical time variations with the $p$, $^3$He,...
GRANDProto300 (GP300) is a prototype array of the GRAND experiment, designed to validate the technique of autonomous radio-detection of astroparticles by detecting cosmic rays with energies between $10^{17}$-$10^{18.5}$ eV. This observation will further enable the study of the Galactic-to-extragalactic source transition region. Since November 2024, 46 out of 300 antennas have been operational...
Observation of Diffuse Supernova-Neutrino Background (DSNB) gives us a new insight into star formation history. The SuperKamiokande (SK) experiment aims to make the first discovery of this flux.
Since 2020, the SK detector has been updated by loading gadolinium (Gd) as a new experimental phase, ‘SK-Gd.’
In the SK-Gd experiment, event selection with delayed coincidence using neutron capture...
Neutrinos emitted from past supernovae are known as Supernova Relic Neutrinos (SRNs). Since the prediction of SRN flux relies on astrophysical inputs such as the supernova rate and cosmic star formation history, the detection of SRNs is expected to provide complementary information to refine these models. KamLAND, a 1-kiloton liquid scintillator, detects electron antineutrinos via inverse beta...
The flux of galactic cosmic rays (GCR) traversing into and inside the heliosphere are modulated by the magnetic activity of the Sun through the heliospheric magnetic field, as the particles are deflected and slowed down by magnetic discontinuities. This modulation of GCR in the heliosphere can be parametrized by the modulation (potential) parameter ϕ, which is estimated using the force field...
As the closest known active galactic nucleus, Centaurus A provides a rich environment for astrophysical exploration, being detected from radio to gamma rays. Recently, very-high-energy gamma rays have been measured by the HESS observatory. The signal is associated with the jet, revealing the presence of relativistic electrons. However, the underlying acceleration mechanism remains uncertain....
The combined data of fluorescence and surface detectors of the Pierre Auger Observatory has recently provided the strongest constraints on the validity of predictions from current models of hadronic interactions [Phys. Rev. D 109 (2024) 102001]. The unmodified predictions of these models on the depth of shower maximum (Xmax) and the hadronic part of the ground signal are unable to accurately...
Beryllium nuclei in cosmic rays are expected to be secondaries produced by the fragmentation of primary cosmic rays during their propagation in the Galaxy. Therefore, their fluxes contain essential information on cosmic ray propagation and sources. Secondary-to-primary flux ratios provide measurements of the material traversed by cosmic rays in their journey through the Galaxy. The 10Be/9Be...
Radio observations of cosmic ray air showers can characterize cosmic ray mass composition, via precise Xmax measurements, at the energies of the likely shift from Galactic to extragalactic sources. Advantages over other methods include lower cost instrumentation and the ability to operate in a range of weather conditions. However, detecting cosmic rays via their radio emission alone amid radio...
The recent detection of TeV neutrino sources by the IceCube Neutrino Observatory demonstrates the detector's advanced capabilities in detecting high-energy astrophysical neutrinos. At lower energies, down to the GeV range, a variety of transient phenomena, such as novae, supernovae, and gamma-ray bursts, are expected to emit neutrinos. Observations of these neutrinos can provide unique...
The DArk Matter Particle Explorer (DAMPE) is a satellite-borne cosmic particle detector which was launched on Dec. 17th, 2015 into a sun-synchronous orbit with the tilt angle of 97.4 degree. The high energy resolution and large geometric acceptance make the detector suitable for the cosmic ray electron (plus positron) measurement. In this work, the time-dependent electron flux was measured...
Suggestion: The radio galaxy M87 has been detected at energies above 1 TeV with a significance exceeding 5$\sigma$ using nearly 10 years of data from the HAWC observatory. To gain further insight into the nature of this emission, we model it with different physical scenarios, ranging from a simple Synchrotron Self-Compton leptonic model to hadronic models. We constrain the physical parameter...
newASTROGAM is a breakthrough mission concept for the study of the non-thermal Universe from space with gamma rays in the energy range from 100 keV to 3 GeV. It is based on an advanced space-proven detector technology, which will achieve unprecedented sensitivity, angular and energy resolution combined with polarimetric capability. Since the MeV gamma-ray energy range is the most...
We present COSMICA, an opensource high-performance GPU-accelerated numerical code for modeling cosmic ray solar modulation, and its application to study CR diffusion parameters. Developed within the framework of the ICSC-Italian Research Center on High-Performance Computing, Big Data and Quantum Computing (Spoke-3), COSMICA is undergoing continuous software optimization to maximize efficiency...
Over the past decade, ground-based array experiments have observed a notable muon deficit when simulating extensive air showers (EAS) induced by high-energy cosmic rays, compared to experimental measurements. This discrepancy is referred to as the muon puzzle. In this report, we present the first investigation on this topic at the China Jinping Underground Laboratory (CJPL), which, with its...
Clock isotopes such as beryllium-10 provide a unique Galactic cosmic ray lifetime measurement related to the size of the propagation halo in the Milky Way. There have yet to be high-precision measurements of beryllium-10 above 2 GeV/n. The High Energy Light Isotope eXperiment (HELIX), a balloon-borne magnet spectrometer, directly measures a cosmic ray’s charge, magnetic rigidity, and velocity...
Radio detection of extensive air showers induced by ultra-high energy cosmic rays has significantly advanced in recent decades. Observables such as shower energy and depth of maximum development are largely derived by comparing experimental data with Monte Carlo simulations, making it essential to assess the systematic uncertainties associated with the simulation models. In this work, we...
Very high energy (>200 GeV) gamma-ray emission was discovered from the blazar 1ES 1028+511 located at redshift z= 0.361 as part of the VERITAS AGN Discovery Program. It is classified as an extreme high-frequency-peaked BL Lac object (EHBL) and is potentially an interesting object for multi-messenger studies. This EHBL was selected for observation because of its bright X-ray emission and its...
The interest in the study of the global features of the modulation of galactic cosmic rays has been increasing since the 23rd solar minimum. This is supported by various detectors such as PAMELA, AMS-02 and HEPD01, providing cosmic ray particles measurements at Earth over two complete solar cycles i.e., the 23rd and 24th. These exceptional observations provide an opportunity for enhanced...
Cosmic rays can induce extensive air showers whose development takes place entirely inside the atmosphere, without reaching the ground. These atmosphere-skimming events have been detected with balloon-borne experiments such as ANITA and EUSO-SPB2. In this work, we evaluate the possibility of estimating the energy of an atmosphere-skimming cosmic ray shower through measurements of radio pulses....
The well-known blazars, Markarian 421 (Mrk 421) has been detected with high significance by LHAASO. Since the observation of gamma radiation from blazars provides insights into the physical processes occurring in their relativistic jets making it crucial to study their broad-band spectral energy distribution (SED). For this purpose, contemporaneous data in the gamma-ray band along with X-ray...
MeV gamma-ray observations are important to deepen our understanding of the physics of high energy phenomena such as active galactic nuclei and gamma-ray bursts. Particularly an all-sky MeV gamma-ray facility with a good localization accuracy of about 1 degree can significantly increase the number of follow-up observations of transient events, increasing opportunities for multi-messenger...
The Radio Neutrino Observatory Greenland (RNO-G) is being constructed at Summit Station in Greenland. It seeks to detect the radio emission of neutrinos interacting in the 3~km thick ice. Radio detection of neutrinos is sensitive to neutrinos above 10 PeV and therefore complements existing optical detectors. RNO-G currently consists of 8 out of planned 35 stations, each combining the signals...
The Square Kilometre Array (SKA) is a radio telescope currently under construction in South Africa and Australia.
Its low-frequency part (50-350 MHz), located in Australia, features nearly 60,000 antennas in a core region of about 1 km diameter.
With such an extreme antenna density, surpassing e.g. LOFAR by two orders of magnitude, this observatory is well equipped to make the most precise...
The detection of high-energy astrophysical neutrinos by IceCube has opened a new window on our Universe. While IceCube has measured the flux of these neutrinos at energies up to several PeV, much remains to be discovered regarding their origin and nature. Currently, the discovery of point sources of neutrinos is hindered by atmospheric neutrino backgrounds; likewise, astrophysical neutrino...
ALICE experiment at CERN Large Hadron Collider, located 52 meters underground, carried out a cosmic data-taking campaign in the period 2015-2018 corresponding to 62.5 days of live time. In this work the analysis of these data is limited to multimuon events defined as events with more than four detected muons. In particular the muon multiplicity distribution (MMD) is studied in the...
A new full model of the atmospheric transport of cosmogenic 10Be is presented which allows linking its production by cosmic rays with the measured concentrations in ice cores. The model is based on the focused SOCOL‐AERv2‐BE chemistry‐climate model coupled with the CRAC:10Be isotope production model. It includes all the relevant atmospheric processes and allows computing the isotope...
Ultra-High-Energy (UHE, E >100 TeV) gamma rays are one of the few channels to search for and study galactic PeVatrons. Among the most promising PeVatron candidates are the many UHE gamma-ray sources that have recently been identified on the Galactic Plane. Ground-based particle detectors see these sources as extended rather than point-like, and current generation Imaging Atmospheric Cherenkov...
We report the latest results on the properties of Ar and Ca cosmic rays nuclei fluxes in the rigidity range 2.5 GV to 3 TV based on 0.2 million Ar and 0.3 million Ca nuclei collected by the AMS. We observe that Ar and Ca fluxes are well described by the sums of a primary cosmic ray component (Si flux) and a secondary cosmic ray component (F flux). With our measurements, the abundance ratios at...
The GRAPES-3 (Gamma Ray Astronomy at PeV EnergieS phase-3) is a globally recognized experiment that detects cosmic rays with energies in the range from 10$^{13}$ eV to 10$^{16}$ eV. It has an excellent core-reconstruction resolution, approximately 0.5 meters at 1 PeV. We are designing a radio antenna array with 60-70 antennas, envisaged to function along with the array of scintillator...
The High-Altitude Water Cherenkov (HAWC) observatory, located in Volcán Sierra Negra, México, is designed to detect very high-energy (VHE) gamma rays and has provided continuous sky observations in the range of hundreds of GeV to hundreds of TeV since it began operations in 2015. Over nine years (2015–2024), HAWC has revealed the evolution of the light curve of the blazar Markarian 421 (Mrk...
The study of the muon content in extensive air showers (EAS) is relevant for understanding the origin and nature of cosmic rays. Moreover, muons serve as a sensitive observable to hadronic interactions in air showers, offering insight into high-energy physics processes. However, discrepancies between measured and predicted shower muon content have been reported by some EAS observatories at...
DAMPE is a space-based particle detector designed to study high-energy cosmic rays, including electrons, gamma rays, and atomic nuclei. Since its launch in December 2015, it has been operating smoothly for over nine years, recording more than 1.6 billion cosmic-ray particles. DAMPE data have already confirmed spectral breaks for light elements as a hardening break at a few hundred GeV/n and...
The main aim of the SAMADHA project is to monitor the cosmic ray neutron
spectrum and dose at very high altitudes in the South Atlantic Anomaly
region during the maximum activity of the 25$^{th}$ solar cycle.
The experimental setup for this measurement consists of an Extended Bonner
Sphere System and a commercial Rem counter. A linear energy transfer
spectrometer to measure the...
PUEO, the Payload for Ultrahigh Energy Observations, is a long duration balloon-borne experiment with the primary science goal of detecting the impulsive Askaryan emission from ultrahigh energy (>1 EeV) neutrinos interacting in the ice sheet of Antarctica. The ultrahigh energy neutrino flux is yet to be detected, and so a successful measurement by PUEO will give us information about the where...
The Taiwan Astroparticle Radiowave Observatory for Geosynchrotron Emissions (TAROGE) is an antenna array located atop the high mountains along Taiwan’s eastern coast, oriented toward the ocean. It is designed to detect near-horizon extensive air showers (EAS) induced by ultra-high-energy cosmic rays (UHECRs) and Earth-skimming ultra-high-energy tau neutrinos. The TAROGE array offers several...
At large zenith angles, the electromagnetic component of ordinary air showers is significantly attenuated by the atmosphere long before reaching ground level. The observation of Horizontal Air Showers (HAS) provides a "well-shielded laboratory" for detecting penetrating particles, such as high-energy muons and cosmic neutrinos, which leave a distinctive signature in this environment.
In this...
Reconstructing the longitudinal profile of extensive air showers, generated from the interaction of cosmic rays in the Earth's atmosphere, is crucial to understand their mass composition, which in turn provides valuable insight on their possible source of origin. Furthermore, the substructures within the profile allow us to probe the intricate particle interactions that occur within these air...
Exoplanets orbiting red dwarf stars in the habitable zone are easier to detect than those orbiting Sun-like stars. In recent years, there has been increased interest in modelling the Galactic cosmic ray fluxes reaching exoplanets orbiting stars other than the Sun. This is because Galactic cosmic rays can affect exoplanet habitability by for instance, driving the formation of prebiotic...
We present the properties of the flux of primary cosmic Ni nuclei in the rigidity range from 3 GV to 1.3 TV, based on 30,000 nuclei collected by Alpha Magnetic Spectrometer during 13.5 years of operation from May 2011 to November 2024. The rigidity dependence of the Ni/Fe flux ratio will be equally discussed.
In this talk, I will present the first study of an outburst from a high synchrotron peaked blazar (HSP) with X-ray polarimetry and very high-energy (VHE; E >0.1 TeV) gamma ray measurements. While the mechanisms driving flares in blazar jets remain poorly understood, the associated spectral variations imply that particle (re)acceleration must play a central role. For HSPs, the advent of...
Air-Shower Universality is a framework that describes the regularity in the longitudinal, lateral, and energy distributions of electromagnetic shower particles, motivated by solutions to the cascade equations. We employ a universality-based model of shower development that incorporates hadronic particle components to reconstruct observables from extensive air showers produced by...
The muon content predicted by hadronic interaction models falls short of describing the data from multiple air shower experiments. This discrepancy, known as the Muon Puzzle, poses significant challenges for mass composition studies and limits our understanding of the origins and acceleration mechanisms of ultra-high-energy cosmic rays. The recent releases of the EPOS LHC-R and QGSJET-III...
Young massive stellar clusters (YMSCs) have emerged as energetic non-thermal sources, after the recent observation of extended gamma-ray emission by a dozen YMSCs. The large size of their gamma-ray halos, of the order of the excavated bubble from the collective wind, makes the detection of individual YMSCs rather challenging because of the low surface brightness. As a result, the emission from...
The Dark Matter Particle Explorer (DAMPE) is a calorimetric, satellite-borne detector that has been operating in orbit for over nine years. One of its key scientific objectives is measuring the flux of cosmic-ray nuclei, crucial for understanding the origins of cosmic rays and their propagation mechanisms.
Nickel, one of the most stable elements alongside iron, is the most abundant heavy...
I will show that current mm-to-X-ray polarization trends observed during recent IXPE campaigns for high-synchrotron peaked blazars and the ROBOPOL trend for Fermi blazars, which relate the fractional polarization to the peak frequency of the synchrotron emission, can be successfully reproduced by a multi-zone scenario without the need for an energy-stratified scenario. I will also discuss some...
To detect ultra-high-energy neutrinos, experiments such as ARA and RNO-G target the radio emission induced by these particles as they cascade in the ice, using deep in-ice antennas at the South Pole or in Greenland. In this context, it is essential to first characterize the in-ice radio signatures from cosmic ray induced particle showers, which constitute a primary background for neutrino...
Solar energetic particles (SEPs) and cosmic rays are high energy particles that impact Earth's atmosphere. One key way that these particles interact with the material in the atmosphere is by ionising atoms and molecules, resulting in changes in the atmosphere’s chemistry. They may even have contributed to the formation of prebiotic molecules, the “building blocks” for life, on Earth's surface...
The GRAPES-3 experiment, located in Ooty, India, consists of a densely packed array of 400 plastic scintillator detectors and a large area ($560 m^2$) muon telescope. The muons produced in extensive air showers (EAS) are key observables for analyzing the primary cosmic ray composition. The GRAPES-3 muon telescope (G3MT) measures the muonic component in the EAS by counting the reconstructed...
With a large field-of-view and almost full duty cycle, LHAASO-WCDA is appropriate to monitor the VHE emission from extra-galactic transient sources like GRBs and AGNs, or galactic variable sources like binaries, pulsars and nova. However, these sources either suffer from severe EBL absorption at high energies or have an energy spectral cutoff at sub-TeV range, making them faint or even...
Observation of high-energy neutrinos from the direction of the nearby active galaxy, NGC 1068, was a major step in identifying the origin of high-energy neutrinos. This observation revealed that high-energy neutrinos originated at the heart of active galaxies, which are opaque to very-high-energy gamma-ray emission. This realization is further reinforced by the multimessenger picture for the...
The atmosphere provides a large set of experimental conditions on which cosmic-ray induced high-energy hadron interactions can take place. These conditions include: sudden changes in the atmospheric pressure, temperature, and in the local electric and magnetic fields. In this talk we introduce the Piritakua (flash of lightning, in the language of the pre-Columbian Purépecha Empire in Mexico)...
Much has been learned about Galactic cosmic rays in the past decade: On the observational side, the spectra of cosmic ray nuclei have been directly measured with high precision, resolving chemical composition up to TV rigidities. At even higher rigidities, direct detection is making contact with indirect observations from air shower arrays. A number of breaks have been found in the nuclear...
The pursuit of understanding the structure and origin of Galactic and extragalactic magnetic fields is a central science driver for current and future radio telescope surveys. Magnetic fields are pervasive and thought to be a critical driver in many astrophysical processes across all physical scales from solar flares to exoplanet habitability, stellar evolution, galactic turbulence, cosmic ray...
In this presentation, I discuss the recent highlights from eROSITA observations.
In particular, I will discuss the findings about our Milky Way and its bubbles as well as measurements of the circumgalactic medium.
In 2023, multiple pulsar-timing-array collaborations reported evidence for a low-frequency background of gravitational waves. The amplitude and spectral shape of the background are consistent with emission from the population of supermassive black-hole binaries at the centers of galaxies, but more exotic sources are not excluded. I will explore the collection and analysis of...
MeV cosmic rays can penetrate dense molecular clouds and oftentimes dominate the ionisation, thus contributing to the physical and chemical dynamics of star forming regions. The effect of cosmic rays can be quantified by their ionisation rate. Interestingly, the ionisation rate predicted from the locally measured cosmic-ray fluxes is one to two orders of magnitude lower than the observed...
The Large Area Telescope onboard the Fermi Gamma-ray Space Telescope (Fermi-LAT) has surveyed the sub-GeV/GeV gamma-ray sky and achieved high statistics measurements since 2008. However, observation at low galactic latitudes remains difficult owing to the lack of the angular resolution, and new issues following the operation of Fermi-LAT have arisen.
We devised a precise gamma-ray observation...
Accurately measuring the energy of shower particles reaching the ground remains a challenge due to the inherent limitations of typical cosmic ray experiments. In this work, we present two experimental strategies to determine the energy spectra of the electromagnetic and muonic components of extensive air showers, leveraging a single hybrid detector station within a regular cosmic ray array....
Anisotropy of galactic cosmic-rays (GCRs) represents their momentum-space distribution in the interplanetary plasma, playing a key role in revealing the solar modulation of GCRs. The Global Muon Detector Network (GMDN; http://hdl.handle.net/10091/0002001448) has been a unique means to observe the anisotropy, thanks to its excellent angular resolution, angular acceptance, and statistics....
Even if in a partial detector configuration, a neutrino event of exceptional energy (about 220 PeV) was detected with the KM3NeT-ARCA detector [Nature 638, 376–382 (2025)]. This ultra-high-energy event lies in an unexplored energy range where neutrinos have been predicted but never observed until now.
At the time of the detection, on February 13 2023, the ARCA detector consisted in 21...
When ultra-high-energy cosmic rays (UHECRs) interact with ambient photon backgrounds, a flux of extremely-high-energy (EHE), so-called cosmogenic, neutrinos is produced.
The observation of these neutrinos with IceCube can probe the nature of UHECRs. We present a search for EHE neutrinos using 12.6 years of IceCube data. The non-observation of neutrinos with energies $>~10 \, \mathrm{PeV}$...
The Radar Echo Telescope for Cosmic Rays (RET-CR) is a prototype experiment for the future neutrino detector, the Radar Echo Telescope for Neutrinos (RET-N). It is deployed at Summit Station in Greenland, with a full data-taking run conducted in the summer of 2024.
This experiment utilises the radar technique to search for an in-ice secondary cascade produced when the core of a high-energy...
SENSEI (Sub-Electron Noise Skipper Experimental Instrument) is the first experiment to implement silicon skipper CCDs to search for dark matter. Skipper-CCDs can resolve single electrons in each of millions of pixels, which allows for the low energy threshold required to detect sub-GeV dark matter interacting with electrons. SENSEI recently measured the lowest event rates containing one...
The simulation of particle cascades is an essential foundation for the analysis chains of many astroparticle physics experiments, irrespective of whether they investigate primarily charged cosmic rays, very high-energy photons or neutrinos, or even dark matter. The most widely used software for simulating such particle showers is CORSIKA, originally developed as COsmic Ray Simulation for...
Solar activity variations strongly impact the modulation of the flux of low-energy Galactic Cosmic Rays (GCRs) reaching the Earth. The secondary particles, which originate from the interaction of GCRs with the atmosphere, can be revealed by an array of ground detectors. We show that the low-threshold rate (scaler) time series recorded over 16 years of operation by the surface detectors of the...
Low-energy cosmic rays (LECRs) are a vital ingredient of the interstellar medium (ISM). Unlike ionizing radiation, they can penetrate deeply in dense environments and are considered as the main ionizing agent for the core of molecular clumps, ultimately determining their stability against gravitational collapse. Young massive star clusters are known to shape the surrounding ISM, excavating...
The simulation of extensive air showers is pivotal for advancing our understanding of high-energy cosmic ray interactions in Earth's atmosphere. The CORSIKA 8 framework is being developed as a modern, flexible, and efficient tool for simulating these interactions with a variety of high-energy hadronic models. We present the ongoing implementation and validation of Pythia 8/Angantyr within...
We are advancing precise observations of cosmic gamma rays in the sub-GeV/GeV energy range using a large-scale nuclear emulsion telescope with high angular resolution (0.1° at 1 GeV), deployed on a balloon. We conducted balloon experiments in 2011, 2015, 2018, and 2023. In 2018, we achieved the first detection of an astronomical gamma-ray source and imaged the Vela pulsar with the worldʼs...
Understanding the heliospheric modulation of galactic cosmic rays is essential for studying the acceleration and propagation processes of these particles, as well as for establishing models of radiation exposure and associated risks in space missions. Here we present our efforts in the development of an effective data-driven model describing the time- and energy-dependent solar modulation...
The PandaX-4T experiment, a multi-ton scale liquid xenon detector, has achieved leading-edge physical results across multiple research targets with its latest accumulated exposure. Leveraging its unprecedented sensitivity and low background capabilities, PandaX-4T has conducted extensive searches for Weakly Interacting Massive Particles (WIMPs) and other exotic DM candidates, setting stringent...
In this work we show that there is a strong dependence of the radio lateral distribution function (LDF) electric field amplitudes at ground level on the position of the shower maximum ($X_{max}$) in the atmosphere, even when accounting for differences in the electromagnetic (EM) energy of the showers. This $X_{max}$ dependence can be explained in terms of two competing effects on the measured...
The problem of the excess of muons in extensive air showers (EAS) initiated by very high energy cosmic rays remains an intriguing challenge even for modern upgraded and retuned models of high energy hadron interactions. Collider experiments also demonstrate many indications of some new processes taking place in pp, pA and AA interactions. While some improvements come from the consideration of...
Precise measurements of the composition of cosmic rays in the energy range of $10^{17}-10^{18}\,$eV could provide crucial insights into the long-standing questions about the origin and acceleration of these particles. Ground-based experiments typically rely on determining the position of the extensive air shower maximum ($X_\rm {max}$) to identify the type of cosmic ray particle. One...
The Central Molecular Zone (CMZ), located in the centre of the Milky Way, is a roughly cylindrical structure of molecular gas extending up to $\sim 200$ parsecs around the supermassive black hole Sagittarius A$^*$. The average H$_2$ ionisation rate in the CMZ is estimated to be $2 \times 10^{-14} \, \mathrm{s}^{-1}$, which is 2–3 orders of magnitude higher than anywhere else in the Galaxy. Due...
The NEWS-G experiment uses spherical proportional counters (SPC) to probe for low mass dark matter. An SPC is a metallic sphere filled with gas with a high-voltage anode at its centre producing a radial electric field. The interaction between a dark matter particle and a nucleus can cause ionization of the gas, which leads to an electron avalanche near the anode and a detectable signal.
The...
The Trinity Neutrino Observatory aims to detect tau neutrinos in the energy range of 1 PeV to 10 EeV. We are developing the observatory in three stages. The first stage, known as the Trinity Demonstrator, was deployed in Fall 2023. The Demonstrator serves as a pathfinder for the full observatory and will inform the design of the first Trinity Telescope. In this presentation, I will discuss the...
Electromagnetic dissociation (EMD) is a well-known process which has been extensively studied with accelerator beams. On the contrary, the influence of EMD on cosmic-ray propagation in the atmosphere and in the Galaxy is still somewhat unclear. For example, the mass composition is one of the most important ingredients to understand the origin of ultra-high energy cosmic rays. It can be...
The CUbesat Solar Polarimeter (CUSP) project is a CubeSat mission planned for a launch in low-Eart orbit and aimed to measure the linear polarization of solar flares in the hard X-ray band by means of a Compton scattering polarimeter. CUSP will allow to study the magnetic reconnection and particle acceleration in the flaring magnetic structures of our star. CUSP is a project in the framework...
DarkSide-20k is a next-generation multi-ton dark matter experiment currently being built at the INFN Gran Sasso National Laboratory (LNGS). Building on the success of the DarkSide-50 detector, which has been in operation since 2015, DarkSide-20k will feature a dual-phase Liquid Argon Time Projection Chamber (TPC) with a 20-tonne fiducial mass (50-tonne active), designed to achieve...
The DEAP-3600 experiment is a direct dark matter detection experiment located 2 km deep underground at SNOLAB, Canada. 3.3 tonnes of liquid argon contained in an acrylic vessel instrumented with 255 PMTs are used for this experiment. It aims to measure nuclear recoil of argon caused by weakly interacting massive particles (WIMPs), a potential dark matter candidate. Since 2019, DEAP-3600 has...
Radio emissions from extensive air showers (EAS) provide a valuable tool for detecting ultra-high-energy (UHE) astroparticles. In this context, several radio arrays focus on detecting highly inclined EAS, as this enables the observation of Earth-skimming UHE neutrinos, in addition to cosmic rays and gamma rays.
The reconstruction of such inclined events relies heavily on a thorough...
We present a combined tune of the Pythia 8 event generator using accelerator data and evaluate its impact on air shower observables.
Reliable simulations with event generators are essential for particle physics analyses, achievable only through advanced tuning to experimental data. Pythia 8 has emerged as a promising high-energy interaction model for cosmic ray air shower simulations,...
Supernova remnants (SNRs) have long been suspected to be the primary sources of Galactic cosmic rays. Over the past decades, great strides have been made in the modelling of particle acceleration, magnetic field amplification, and escape from SNRs. Yet while many SNRs have been observed in nonthermal emission in radio, X-rays, and gamma rays, there is no evidence for any individual object...
The solar steady emission in gamma rays is due to the interactions of Galactic Cosmic Rays with the solar atmosphere and with the low-energy solar photon field via inverse Compton scattering. The emission is sensitive to the magnetic field nearby the Sun and to the cosmic-ray transport in the magnetic field in the inner solar system. Modeling the inverse Compton emission in the presence of a...
Outflows from star-forming regions are thought to have a profound effect on galaxy evolution. The role of cosmic rays in such outflows is however not clear at present. We report on the discovery of a cosmic-ray loaded outflow from the young massive star cluster Westerlund 1, which is known to accelerate cosmic rays to several tens of TeV. The outflow manifests itself as a ~150 pc-diameter GeV...
Hyper-Kamiokande (Hyper-K) is a multi-purpose next-generation neutrino experiment aiming to start its operation in 2027.
The Hyper-K water Cherenkov detector consists of a two-layered cylindrical ultra-pure water tank with a height (diameter) of 64 (71) meters. The inner detector will be equipped with twenty thousand twenty-inch photomultipliers and 800 multi-PMT modules. These sensors detect...
SABRE is an international collaboration that will operate similar particle detectors in the Northern (SABRE North) and Southern Hemispheres (SABRE South). This innovative approach distinguishes possible dark matter signals from seasonal backgrounds, a pioneering strategy only possible with a southern hemisphere experiment. SABRE South is located at the Stawell Underground Physics Laboratory...
Great advances are happening in our understanding of our Galaxy and its physical phenomena, courtesy of missions such as TIGERISS (Trans-Iron Galactic Element Recorder on the International Space Station), which will be the first single instrument to look at elemental abundances spanning B to Pb. However, the accurate interpretation of these advanced observational data is contingent upon...
Stellar wind termination shocks are considered potential sites for efficient particle acceleration, allowing an explanation for the overabundance of Ne²² observed in cosmic rays (CRs) through Wolf-Rayet stars (WRs) and providing a minor but necessary contribution to the observed flux of Galactic CRs. However, only a few powerful star clusters such as Westerlund 1 and Cygnus OB2 have been...
In this talk I will introduce the DarkSide-20k detector, now under construction in the Gran Sasso National Laboratory (LNGS) in Italy, the largest underground physics facility in the world devoted to astroparticle physics. The experimet is designed to directly detect dark matter by observing weakly interacting massive particles (WIMPs) scattering off the nuclei in 20 tonnes of...
The origin of ultra-high-energy cosmic rays (UHECRs) is one of the most intriguing mysteries in the astroparticle physics and high-energy physics. Since UHECRs with light mass compositions are less deflected by the Galactic and extragalactic magnetic fields, their arrival directions are more strongly correlated with their origins. Charged-particle astronomy with UHECRs is hence a potentially...
Galactic cosmic rays (GCRs) are high-energy charged particles originating from the Milky Way and widely distributed throughout the heliosphere. The space radiation environment induced by GCRs significantly impacts spacecraft operations. Numerical modeling provides a cost-effective approach to simulate space radiation environments, thus serves as a critical tool for predicting and evaluating...
The Jiangmen Underground Neutrino Observatory (JUNO) is a state-of-the-art neutrino physics experiment located in South China. With 20 ktons of ultra-pure Liquid Scintillator (LS), JUNO aims to achieve groundbreaking measurements, including the determination of Neutrino Mass Ordering (NMO) and the precise measurement of three neutrino oscillation parameters with sub-percent precision. The JUNO...
Normally, cosmic ray detectors are based on materials where ions or photons are generated as a result of the passage of radiation through the materials, and ions or photons are collected to detect, study, and measure the incident radiation. To combine in one technique, both the ion and photon collection, we planned, designed, constructed, and used a small cosmic ray detector based on one $10...
The interest in the origin and modulation of cosmic ray deuterons is expected to increase significantly now that observations from AMS-02 and PAMELA detectors have become available. Observations made by AMS-02 reveal the spectral shape and features of galactic deuteron over the rigidity range 1.92 GV – 19.5 GV, whereas that from PAMELA are at a lower rigidity, from 0.75 GV – 2.5 GV. These...
Ultra-high-energy cosmic rays (UHECRs) are the most energetic particles ever detected. Their production mechanisms remain unknown, but the conditions in which they are generated are likely to be extreme. Cosmic rays that achieve the highest energies are rare, and their flux at Earth is extremely low. As a result, next-generation experiments with large effective areas are required and under...
Young massive star clusters (YMSCs) can produce gamma rays in the very-high-energy (VHE, E>100 GeV) range and have been proposed as sources that can accelerate cosmic rays up to PeV energies. Observations with current instruments have lead to the detection of only a few YMSCs but future instruments should significantly increase this number. However, the details of the production of the VHE...
Atmospheric muons produced in cosmic-ray air showers are classified as conventional muons from pion and kaon decays and prompt muons from heavy hadron decays. Conventional muons dominate at lower energies, and the prompt component becomes more significant at PeV energies and above. Precisely measuring the atmospheric muon flux from a few GeV to several PeV is valuable for advancing our...
The study of non-gravitational effects of Dark Matter (DM) is a growing field of research, leading to the development of numerous dedicated experiments. Astrophysical and cosmological observations show that the galactic component of DM is non-relativistic; this results in a rapid loss of sensitivity to sub-GeV DM masses in Direct Detection experiments with nuclear targets sensitive to...
Any stars permanently loose small amounts of mass during their lifetimes. This mass is propelled outward at velocities in the range 100 to 3000 km/s at ionization temperatures forming a continuous flow called stellar wind. As cosmic rays permanently and ubiquitously pervade the Galaxy, while impacting on stellar winds, loose energy.
This is empirically known since 70 years. Due...
Cosmic-ray acceleration up to PeV energies has been suggested to take place in massive and young stellar clusters. The formation of a strong termination shock driven by the collective action of stellar winds in compact clusters offers a promising location where efficient particle acceleration might take place over Million year timescales. Moreover, the impulsive acceleration from supernova...
The ANTARES detector was the first neutrino telescope in seawater, operating successfully from 2006 to 2022 in the Mediterranean Sea. All challenges related to the operation in the deep sea were accurately addressed by the collaboration. Deployment and connection operations have become smoother over time; data taking and constant re-calibration of the detector due to the variable environmental...
The origin of ultra-high-energy cosmic rays is still an open question, requiring next-generation observation technology. The CRAFFT project is developing a next-generation fluorescence detector designed for low-cost and fully automated observations with a simple structure. In this study, we report the successful detection of ultra-high-energy cosmic ray air showers using a prototype telescope...
The MoonRay project is carrying out a concept study of a permanent lunar cosmic-ray (CR) and gamma-ray observatory, in view of the implementation of habitats on our satellite. The idea is to build a modular telescope that will be able to overcome the limitations, in available power and weight, of the present generation of CR instruments in Low Earth Orbit, while carrying out high energy...
The seasonal variation of single muons is a well-understood phenomenon, mainly driven by a positive correlation with atmospheric temperature fluctuations. However, the rate of multi-muon events measured by several experiments has revealed an opposite seasonal modulation in multi-muon events, which remains unexplained by any previous studies using CORSIKA simulations. For the first time, we...
The ANTARES neutrino telescope operated from 2007 to early 2022 at the bottom of the Mediterranean Sea, with the primary goal of detecting neutrinos from astrophysical sources. Among these, variable and transient sources are particularly promising, as the timing of neutrino arrivals provides an additional distinguishing feature between signal and background, complementing energy and spatial...
Cosmic rays are detected in two ways: by detecting photons or by detecting ions, which are produced when cosmic radiation interacts with a material medium, such as water or plastic. Cosmic radiation is composed of a variety of elementary particles and heavy nuclei, but especially muons, which are the most abundant, with an electrical charge, at sea level. To study this radiation, we have...
Massive Star Clusters (SCs) have been proposed as important CR sources, with the potential of explaining the high-energy end of the Galactic cosmic-ray (CR) spectrum, that Supernova Remnants (SNRs) seem unable to account for. Thanks to fast mass losses due to the collective stellar winds, the environment around SCs is potentially suitable for particle acceleration up to PeV energies and the...
I discuss the bounds on WIMP-proton and WIMP-neutron couplings of spin-independent and spin-dependent long-range interactions via massless mediator. I update the bounds in the Standard Halo Model for direct detection and the neutrino signal from WIMP annihilation in the Sun, and set halo-independent bounds using the single-stream method.
In the case of a massless mediator the capture rate...
High-energy cosmic rays enter Earth's atmosphere where they interact with atmospheric particles to generate charged mesons that subsequently decay into muons. As the atmospheric temperature rises, the density decreases, increasing the mean free path of pions and kaons and thus their likelihood of decaying into cosmic ray muons. The positive correlation that results as a consequence of this...
The NEWS-G experiment, located at the Sudbury Neutrino Observatory (SNO) in Canada, is searching for Weakly Interacting Massive Particles (WIMPs) in the sub-GeV mass range. This direct dark matter detection experiment uses Spherical Proportional Counters (SPCs) as detectors, which measure nuclear recoils in noble gases. Since nuclear recoils are quenched compared to electronic recoils, precise...
The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) Balloon with Radio (PBR) is an instrument designed to be borne by a NASA suborbital Super Pressure Balloon (SPB), in a mission planned to last as long as 50 days. The PBR instrument consists of a 1.1 m aperture Schmidt telescope, similar to the POEMMA design, with two cameras in its hybrid focal surface: a Fluorescence Camera (FC) and...
The observation of Galactic neutrinos, confirmed by IceCube in 2023, marks a major milestone in astroparticle physics. Underwater detectors like ANTARES, with superior angular resolution compared to IceCube DNN in their published results, provide a unique opportunity to refine our understanding of hadronic processes occurring in the Milky Way. By testing and fitting different phenomenological...
As measured by neutron monitors the flux of galactic cosmic rays exhibits non-statistical fluctuations at all observed timescales. Many of these fluctuations can be identified with specific structures in the solar wind. There is also a rather steady diurnal variation due to cosmic ray streaming in the overall pattern of solar modulation. There is also a spectrum of fluctuations usually termed...
Recent Fermi LAT observations of nearby giant molecular clouds show deficits in the gamma-ray residual map when the expected diffuse emission is modelled assuming uniformly distributed cosmic rays (CRs) [1]. The authors pointed out that the observed emission “holes” reflect the lack of penetration of <∼10 GeV CRs into denser regions, and proposed that the CR deficit is caused by slower CR...
The Physics of the Cosmos (PhysCOS) Program is one of three focused programs contained within NASA's Astrophysics Division (APD). PhysCOS lies at the intersection of physics and astronomy and has the goal of exploring some of the most fundamental questions regarding the physical forces and laws of the universe. The PhysCOS Program Analysis Group (PhysPAG) serves as a community-based,...
Massive Star Clusters (SCs) have been proposed as additional contributors to Galactic Cosmic rays (CRs), to overcome the limitations of supernova remnants (SNRs) to reach the highest energy end of the CR spectrum. Thanks to fast mass losses due to the collective stellar winds, the environment around SCs is potentially suitable for particle acceleration up to PeV energies, and their energetics...
We use the reconstructed properties of individual UHECR events to constrain the location of their unknown sources via approximate Bayesian computation. All important propagation effects, including deflections in both Galactic and extragalactic magnetic fields, are implemented via CRPropa 3. We define priors over key parameters, the source position, distance, particle energy at the source, and...
The nature of dark matter (DM) remains mysterious despite decades of indirect, direct and collider searches. Indirect searches for DM attempt to observe the gamma rays produced in DM decay or annihilation. Depending on the DM particle mass, these gamma rays may be in the very-high-energy regime (>100 GeV). The Very Energetic Radiation Imaging Telescope Array System (VERITAS), an imaging...
After thirteen years of operations on board the International Space Station, AMS has performed precise measurements of solar energetic particle (SEP) mostly observed during solar maximum of solar cycle 24 and 25. AMS has collected more than 40 extreme SEP events accelerated during M- and X-class flares and associated with fast coronal mass ejections. AMS detects these SEPs in the GV rigidity...
The International Particle Physics Outreach Group was created, about 30 year ago, to foster public engagement in STEM via the development of “hands on data” activities. The International Master Class programme underwent, since then, a spectacular and steady growth.
However, IPPOG was also setup as a « Forum » where national outreach programs and actors could share information, inspiration,...
Spinning super-massive black holes at the center of galaxies can launch powerful magnetized jets. When these jets are oriented within a few degrees of our line of sight, they are called blazars, active galactic nuclei that exhibit variable, non-thermal emission across the entire electromagnetic spectrum, from radio waves to gamma rays. 3C 279 is an archetypal blazar with a prominent radio jet...
Despite IC 443 being among the most studied Galactic supernova remnants (SNRs) across the entire electromagnetic spectrum, the complex region around it has yet to be clarified. A detailed analysis of IC 443 surroundings yielded the detection of extended GeV gamma-ray emission spatially coincident with the G189.6+3.3 SNR. Despite the lack of a complete radio continuum image, the position and...
G032.8-00.1 (or Kes 78) and G032.4+00.1 are two adjacent (in projection) supernova remnants (SNRs), apart by 0.4 deg. Both remnants have been investigated in the radio and X-ray bands. Both were previously considered to be related with the 2FGL J1850.7-0014c gamma-ray source. However, such an association was abandoned in the latest Fermi-LAT catalogs. The current view supports the detection...
PG 1553+113 is a distant TeV blazar known for its ~2.2-year periodic gamma-ray signal detected by Fermi. We present results from a decade-long, multiwavelength monitoring campaign of this source.
Our analysis confirms the periodicity in gamma-ray and optical bands; however, no significant periodicity is found at TeV and X-ray energies, based on observations with MAGIC and Swift-XRT,...
Dark Matter (DM) remains a great mystery in modern physics. Among various candidates, the weakly interacting massive particles (WIMPs) scenario stands out and is under extensive study. The detection of the hypothetical gamma-ray emission from WIMP annihilation could act as a direct probe of electroweak-scale interactions, complementing DM collider searches and other direct DM detection...
Cosmic muons are a concrete way to introduce the physics of the “infinitely small” in high schools. In France, despite the adverse evolution of the school curriculum in science that has limited the room for this subject in teaching, some teachers and students have developed a wide range of educational activities that are presented during classes or in the context of scientific circles, both as...
Cosmic rays (CRs) are believed to be accelerated via the first-order Fermi process, in which particles undergo scattering by magnetohydrodynamic (MHD) waves in the vicinity of a shock front. In the acceleration region of ultra-high-energy CRs, CR acceleration occurs in relativistic shocks, where the shock speed approaches the speed of light. To accelerate CRs to $10^{20}$ eV, the strong...
An average solar active region (AR) does not usually generate any enhancement in Solar Energetic Particles (SEPs) near Earth. A small subset of regions are able to produce one or a few SEP events and these are typically taking place at times of fairly good magnetic connection with near-Earth locations via the interplanetary magnetic field (IMF). However a small minority of ARs are...
Machine learning has become a vital part of analysis in modern neutrino astronomy, and many recent discoveries would not be possible without it. This approach, however, is limited by the quality of available training data. Located at the South Pole, the IceCube Neutrino Observatory is a neutrino detector sensitive to astrophysical neutrinos from GeV to PeV energies, with ongoing efforts to...
It has been a long-standing paradigm that the bulk of Galactic comic-ray gets accelerated at supernova remnant shocks via diffusive shock acceleration. As observations – both direct and indirect – became better, many features appeared in the cosmic-ray spectra at Earth and in the emission spectra of remnants, that require deviations from the expectation of a simple power-law of accelerated...
The highest-energy cosmic rays (CRs) with energy above $10^{20}$ eV$=100$ EeV are one of the most mysterious particles in the Universe. Recently, Telescope Array Collaboration (2024) detected the second highest energy CR in history, $244\pm29{\rm (stat.)}~^{+51}_{-76}{\rm (sys.)}$~EeV, which is named as `Amaterasu.' Unger and Farrar (2024) reported no existence of candidates among the radio...
We present the results of more than 15 years of Fermi Large Area Telescope (LAT) monitor observations of the high-energy peaked BL Lac object PG 1553+113 at E>100 MeV and E>1 GeV gamma-ray bands, in comparison with optical, radio and X-ray multifrequency monitoring data. A long-lived, 2.1-year periodic modulation, of the gamma-ray flux is continuing to be significant at a 4 sigma level...
The annihilation of dark-matter particles may lead to the production of monochromatic gamma-ray emission. In this contribution, the search for spectral lines in the gamma-ray spectrum using nine years of data collected with the space-borne Dark Matter Particle Explorer is presented. No line signal is found between 5 GeV and 1 TeV in several regions of interest. The constraints on the...
Astrophysics and particle physics both rely on large-scale, complex research infrastructures—from space telescopes and observatories to underground detectors and particle accelerators. While both fields explore fundamental questions about the universe, they also share a common challenge in public engagement: how to make highly technical and abstract science accessible, meaningful and...
Although for classical models of diffusive shock acceleration (DSA) at supernova remnants (SNRs) it is hard to reach PeV energies, SNRs are still believed to contribute a large amount of the total Galactic cosmic-ray luminosity. Nowadays it is clear that SNRs show a significant temporal evolution of those parameters relevant for the transport and acceleration of CRs within and the escape from...
Supernova remnants (SNRs) are known to accelerate particles up to relativistic energies. We have recently discovered a new SNR, G310.7-5.4 at high Galactic latitude using the ASKAP’s EMU and POSSUM surveys at 943.5 MHz (Burger-Scheidlin et al., in prep.). The faint, extended object has an apparent size of 30.6′ × 30.6′ and shows the typical SNR bilateral shell structure. Strong linear...
Exploring Dark Matter (DM) scenarios through the TeV emission from Active Galactic Nuclei (AGNs) has the potential to provide constraints on the existence of DM candidates such as the Axion-like Particles (ALPs). The very high-energy gamma-ray spectrum of nearby AGNs is expected to be attenuated due to pair production interactions with the Extragalactic Background Light (EBL). However, if...
Experimental results by Milagro, HAWC, and ARGO-YBJ have observed variations in the energy spectrum of cosmic rays at TeV scales in different regions of the sky. These findings on the spectral anisotropy provide insights into cosmic ray behavior. This work explores the impact of galactic CR interactions with the heliosphere in creating the observed spectral anisotropy features. Specifically,...
Current experimental observations of true two-dimensional (2D) anisotropy are insufficient: ground-based experiments achieve precise measurements only in right ascension (RA), while space-based experiments currently provide solely upper limits. For ground detector arrays, the accuracy of detector efficiency is lower than the anisotropy amplitude. Most experiments adopt equal-declination (Dec)...
Over the past millennium, only five Galactic supernovae have been observed and recorded by contemporary astronomers, and their current-day counterparts subsequently identified. The remnants of four of these have all been very deeply studied, and ultimately detected, by TeV instruments after exposures of typically hundreds of hours. The measured TeV fluxes range from 1 Crab (by definition) down...
Turbulence-driven magnetic reconnection is increasingly recognized as a crucial mechanism for accelerating cosmic rays (CRs) to ultrahigh energies (UHEs) in magnetized astrophysical environments, ranging from compact sources to more extended regions. In this talk, I will provide an overview of this acceleration process and present a comparative analysis of 3D magnetohydrodynamic (MHD) and...
Increasingly, the major themes of scientific and technological research (and even of fundamental physics, from discoveries at particle accelerators to the new gravitational and multimessenger astronomy), inspire the work of contemporary artists. The dialogue between art and science is one of the most innovative and promising frontiers of contemporary culture. Artistic interpretation and...
Multimessenger and astroparticle astrophysics has revolutionised our way of observing the cosmos, through electromagnetic and gravitational waves, and astroparticles. The way we take and analyse data, and therefore make science, has been changed, so it’s time to bring this change to our communication strategies and the stories we tell.
This field of research exerts on the general public the...
Supernova remnants are known to accelerate particles to relativistic energies on account of their non-thermal emission. Fast variability in the non-thermal synchrotron emission has been detected in multiple remnants and was linked to local properties of the magnetic fields. Further, variations in the long-term radio and x-ray flux have been reported for various objects as well.
RCW86 is one...
The intermediate synchrotron-peaked BL Lac B2 1811+31 (z=0.117) underwent a period of high activity from the optical band to very-high-energy (VHE; 100 GeV < E < 100 TeV) gamma rays in 2020. Following a high-state detection by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope in the high-energy gamma-ray band (HE; 100 MeV < E < 100 GeV), a dedicated multi-wavelength...
Dwarf Spheroidal (dSph) galaxies are very promising laboratories for the indirect search for Dark Matter (DM), due to their low astrophysical background in radio and gamma-ray frequencies.
For the past several decades, the prompt emission from DM annihilation signatures has been explored through modeling and the setting of limits. In addition to the direct annihilation signatures from...
The study of collisionless shocks and their role in cosmic ray acceleration has gained importance through observations and simulations, driving interest in reproducing these conditions in laboratory experiments using high-power lasers. In this work, we examine the role of three-dimensional (3D) effects in ion acceleration at quasi-perpendicular shocks under laboratory-relevant conditions....
Blazars are among the most powerful gamma-ray emitters, displaying rapid variability and extreme spectral properties. In this study, we systematically search for the most extreme high-energy blazars using 12 years of Fermi Large Area Telescope data, aiming to identify instances of spectral hardening in their gamma-ray spectra. This phenomenon is characterized by a flux that decreases with...
Cosmic rays provide crucial insights into astrophysical phenomena and fundamental physics. However, their detection traditionally requires specialized, costly equipment, limiting accessibility for education. This study explores the potential of using commercially available smartphones and tablets equipped with CMOS image sensors for cosmic ray detection. We developed the “Soramame” app...
Current radio interferometers, with their high sensitivity and angular resolution, are uniquely positioned to investigate the predicted faint signals arising from Weakly Interacting Massive Particles (WIMPs). Among the most powerful instruments in the southern hemisphere is MeerKAT, a precursor to the Square Kilometre Array (SKA), which offers world-leading capabilities for probing dark...
We revisit the process of particle-acceleration at magnetised shocks having an oblique large scale magnetic field. We find the surprising result that even in the test-particle limit, curved spectra may be produced.
For many years, diffusive shock acceleration (DSA) has been viewed as one of the central mechanisms to accelerate cosmic rays (CRs). It is applied to many astrophysical...
The propagation of the Solar Energetic Particles (SEPs) in the heliosphere is guided by the large-scale Parker spiral magnetic field. The gradient and the curvature of the magnetic field give rise to drift of the particles’ guiding centres in the direction perpendicular to the magnetic field, leading the SEPs to gradually move away from their initial Parker spiral field lines. SEP propagation...
The Vela SNR region is a bright, nearby and complex region of non-thermal emission which at its centre it contains a powerful pulsar and its associated pulsar wind nebula, commonly known as Vela X. Due to its nature as one of the most local cosmic ray accelerators it has been an object of interest for many studies at the highest energies.
We present a new detailed study of VHE gamma-ray...
Our exploration of the sky at the highest photon energies has recently benefited from a number of major advances, notably the expansion of the spectral window up to the PeV range, the probing of emissions over larger and larger angular scales, and the coverage of significant portions of the Galaxy. Such a broad view can be expected to lead to significant progress in our understanding of the...
Blazars, a subclass of active galactic nuclei (AGN), are known as the strong emission and frequent activities. The blazar PKS 2155-304 is a high synchrotron-peaked BL Lac with redshit $z=0.116$. On 2006 July 28, an extremely remarkable outburst of VHE $\gamma$-ray emission was reported by H.E.S.S from this blazar, with an average flux more than 10 times the quasi-stable-state value. On the...
Intermediate mass black holes (IMBHs), with masses ranging from a hundred and a million solar masses, are hypothesised to be surrounded by dense regions of dark matter known as dark matter spikes, where the annihilation of dark matter particles could produce detectable gamma rays. The detection of dark matter annihilation around IMBHs therefore offers a promising approach for probing the...
On May 11 2024 a train of at least three magnetic cloud connected to fast coronal mass ejections impacted Earth during a very short period of less than 24 hours. In this so complicated solar wind conditions around Earth, a ground level enhancement was observed by neutron monitors the same 11 May at 2 AM just in between of the first magnetic cloud and the second one. In this time, to twins...
In the ultra-high-energy range, cosmic rays (UHECRs) can originate from distances as large as a few hundreds of megaparsecs, limited mainly by interactions with the infrared background light and the cosmic microwave background. Although a modest size, such volume may contain too many sources to be able to discern the origin with the capabilities of current observatories. Furthermore, the...
Collisionless shocks are widely recognized as powerful particle accelerators in space and astrophysical environments, contributing significantly to the nonthermal energy budget across the universe. A fundamental challenge is understanding how collisionless shocks, where Coulomb interactions are negligible, accelerate thermal particles into a nonthermal energy state, leading to a power-law...
Detectors are essential tools for modern astroparticle physics. Found in ground-based and space-borne observatories, they are used to detect, analyse and monitor all types of electromagnetic and particle radiation. Following similar principles, cutting-edge detectors at CERN are used to detect the products of high-energy collisions, allowing scientists to confirm or disprove theoretical models...
In this talk, I will review our recent progress and important findings of the beaming effect and relativistic jet property in gamma-ray blazars detected by the Fermi-Large Area Telescope (Fermi-LAT). Blazars are a particular class of radio-loud Active Galactic Nucleus (AGNs), characterized by many distinctive observational properties, which are due to the relativistic beaming effect. Since the...
Collisionless shocks in relativistically hot ($T \gg mc^2$) plasmas are investigated using the Particle-In-Cell (PIC) simulation. Shocks in space are collisionless shocks, which are mediated by wave-particle interactions rather than the Coulomb collisions. Considering the upstream temperature, shocks can be classified into two types: cold upstream ($T \ll mc^2$) and relativistically hot...
The quest to identify the true nature of dark matter remains one of the most pressing challenges in modern physics. We present here a novel approach to probe DM by analyzing mini spikes in DM density around stellar mass black holes using 14 years of data from the Fermi Large Area Telescope (Fermi-LAT). These mini spikes, formed due to the adiabatic growth of black holes in DM halos, can...
The characterization of the effects of solar disturbances on the Earth's ionosphere is crucial for the monitoring and understanding of space weather. While satellites orbiting outside of the Van Allen belts allow for direct measurements of the ejected particles and of magnetic field perturbations, low Earth orbit spacecraft, such as the China Seismo-Electromagnetic Satellite (CSES-01), provide...
Magnetohydrodynamic (MHD) turbulence plays a fundamental role in shaping the interstellar medium (ISM), influencing cosmic ray transport, star formation, and plasma dynamics. However, identifying the dominant MHD modes—Alfvén, slow, and fast—from observational data remains a significant challenge. In this study, we present a novel refinement of the Synchrotron Polarization Analysis (SPA)...
The origin of cosmic rays has been an active area of research since their discovery over a century ago. Supernova remnants (SNRs) are believed to be able to accelerate cosmic rays up to the ‘knee’ of the observed cosmic-ray spectrum. Although the acceleration at SNR shocks has been extensively modelled, it is still not clear that cosmic rays are able to escape these sources. After...
The Distributed Electronic Cosmic-ray Observatory (DECO) is a project that enables users to detect cosmic rays and other ionizing radiation with their own cell phones. The DECO app treats cellphone cameras as silicon track detectors. Event images are uploaded to a web-based database where users and other members of the public can query, download, and analyze them. A convolutional neural...
Solar eruptive activity has many forms, the most important and well-studied are solar flares, coronal mass ejections, and solar energetic particle (SEP) events. It is mostly unknown what is the upper limit for the intensity of different eruptive activity events. For now, only traces of extreme solar particle events (ESPEs) were discovered in cosmogenic isotope data in datable natural archives,...
CERN Science Gateway opened its doors to the public in autumn 2023. Part of this new education and outreach centre are the exhibitions that combine immersive scenography with interactive exhibits and real scientific objects.
Three exhibitions are available for the public. In Discover CERN visitors learn more about the accelerators and detectors at CERN. Our Universe consists of two parts: in...
Cosmic rays (CRs) remain a key uncertainty in galaxy evolution due to their poorly constrained transport and acceleration in diverse plasma environments. They may play a crucial role in shaping the multiphase structure of the Circumgalactic Medium (CGM), with their impact varying across different phases depending on their transport properties and coupling with the thermal plasma. A central...
Mildly relativistic collisionless plasma shocks allow for a broader range of oblique subluminal mean magnetic field configurations, in contrast to inherently superluminal ultra-relativistic shocks. This enables particle acceleration and heating mechanisms, as well as the generation of electromagnetic waves, driven by particle reflection off the shock. Here, we present our recent results from...
The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based observatory for gamma-ray astronomy, covering a very broad energy range from 20 GeV to beyond 100 TeV. The luminosity function (LF) of very-high-energy (VHE) blazars measures their evolution over cosmic time, constrains their contribution to unresolved radiation fields, and connects them to source populations...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a planned very-high-energy gamma-ray observatory that will provide novel and complementary insights about the southern-hemisphere sky thanks to its high sensitivity, wide field of view, and continuous observation capabilities. Centaurus A (CenA) is an Active Galactic Nucleus that has been detected at TeV energies by the H.E.S.S....
The first detection of gravitational waves in 2015 and the birth of multimessenger astronomy with gravitational waves in 2017 represented a real revolution in the way we observe the cosmos. As communication office of EGO, the institution that hosts the Virgo gravitational wave detector, we are constantly looking for new ways to tell the public about these great milestones, in the most engaging...
We report on the sources of gamma-ray emission above 100 MeV in the very impulsive GOES M3.3 class flare SOL2012-06-03. The >100 MeV emission during the prompt phase displayed a double-peaked temporal structure, with the highest peak occurring 17$\pm$2 seconds after the first peak with a difference in flux of almost a factor of 3. The HXR and gamma-ray time profiles during the impulsive phase...
Dark matter is one of the most important and elusive enduring mysteries of physics in the last century. Gamma ray astronomy offers a possible avenue to determine dark matter’s particle nature through observation of gamma ray by-products of its annihilation or decay. However, it is challenging to formulate a robust dark matter search given our lack of knowledge on dark matter physics. In this...
VER J0521+211 is one of the brightest BL Lac objects detected in the TeV gamma-ray regime, located at a redshift of z=0.108 and 3 deg away from Crab Nebula.It was not included in 1LHAASO catalogue, but manifests with 5.6 sigma in 978-day data from March 2021 to Jan 2024. WCDA enables continuous long term monitor, which will provide important information of the average emission of this blazar...
Chemical abundances in cosmic rays (CRs) are crucial for understanding their origin and acceleration mechanisms. Shock waves formed in high-energy astrophysical phenomena are promising mechanisms for CR acceleration. The chemical composition of the medium through which the shock propagates differs in each high-energy astrophysical phenomenon. Observational experiments of CRs show that the...
The nature of the cosmic ray all-particle spectrum knee has been a long-standing puzzle since its discovery. The high altitude near the shower maxima of cosmic rays in the knee region has enabled the LHAASO experiment to conduct calorimetric energy measurements, significantly reducing the dependence of energy measurement on cosmic ray composition and interaction models typical in ground-based...
Blazars show variability across the entire electromagnetic spectrum and over a wide range of timescales. In some cases, characteristic emission patterns have been observed, such as the multi-year modulation detected in PG 1553+113. Quasi-periodic oscillations (QPOs) can arise from various astrophysical mechanisms, including jet precession, accretion disk instabilities, and binary supermassive...
Pulsar wind nebulae (PWNe) are prominent sources in the very-high energy (VHE) gamma-ray sky, constituting the most numerous identified source class in the H.E.S.S. Galactic Plane Survey (HGPS). They are comprised of energetic particles originating from the pulsar and expanding into the surrounding medium. As such, PWNe are of very high scientific interest as PeVatron candidates, objects that...
The Global Spline Fit (GSF) is a data-driven parameterization of cosmic-ray flux and mass composition. It combines direct and indirect measurements of the cosmic-ray flux of individual elements from 1 GeV to $10^{11}$ GeV, considering their uncertainties. At lower energies, the fluxes are corrected to the local interstellar spectra using the individual data-taking periods of the experiments....
The Pierre Auger Observatory has been operating in Malargüe, Province of Mendoza, western Argentina, for over two decades, significantly advancing our understanding of cosmic rays. Beyond its scientific mission, the installation and operation of the observatory has had profound social, economic, educational and cultural impact on the local community, the region and worldwide.
More than 90%...
The energy spectrum of solar energetic electron (SEE) events carries crucial information on the origin/acceleration at the Sun. We present ten solar energetic electron (SEE) events measured by Wind/3DP at ~1 to 200 keV with a bump break in the electron peak flux vs. energy spectrum. We assume that these bump SEE events consist of two electron populations: primary population (described by the...
Higgsino dark matter (DM) is a well-motivated candidate in supersymmetric theories, with a 1.1 TeV thermal higgsino naturally accounting for the observed DM abundance. Despite its strong theoretical foundation, detecting the higgsino remains challenging.
Direct detection is hindered by its suppressed scattering cross-section and theoretical uncertainties on contaminated background,...
Charged particles accelerated at the forward shocks of supernova remnants (SNRs) likely constitute the majority of the Galactic Cosmic Ray (CR) population. They also play a vital role in regulating the hydrodynamical evolution of their accelerators. For example, efficient CR acceleration at shocks leads to enhanced compression, which in turn alters the distribution of CRs released into the...
The Pierre Auger Observatory has driven the field of ultra-high-energy cosmic ray (UHECR) physics, producing several groundbreaking observations over the last 20 years. One of the most striking findings has been the complex evolution of UHECR mass composition, as revealed by detailed analyses of observables such as the depth of shower maximum (Xmax) and the muon content of showers. As more...
Cosmic rays, discovered in 1912, are high-energy particles originating from outer space. They carry rich information about celestial evolution and the universe and represent the only material samples,which humans can obtain from beyond the solar system.
Cosmic ray observation touches on the frontiers of particle physics and astrophysics. The methods and instruments used in the experiments...
We analyzed multiwavelength data of the BL Lac object S5 0716+714 to investigate its emission mechanisms during a flaring state observed in early 2015. We examined the temporal behavior and broadband spectral energy distributions (SEDs) during the flare. The size of the $\gamma$-ray emission region was estimated based on the variability timescale. To explore the multiwavelength properties of...
Galactic Cosmic Rays (GCRs) are a source of major radiation hazards in space, therefore the forecast and nowcast of their spectrum time evolution during the passage of Coronal Mass Ejections (CMEs) is a desired part of radiation hazard prediction models. GCRs are generated in galactic sources and propagate until they approach the heliopause, where their Local Interstellar Spectrum (LIS) can be...
We present an analysis of ultra-high energy cosmic ray (UHECR) mass composition based on four years of data collected by Telescope Array’s expansion project, TA×4. Reconstructing events in hybrid mode, combining information from both the fluorescence detectors (FDs) and surface detectors (SDs), we measure the mass composition of UHECRs using the distribution of the depth of air shower maxima...
PKS 2155-304 is a well-known high-frequency peaked BL Lac (HBL) at redshift z=0.116, which has been extensively studied across the electromagnetic spectrum due to its rapid and large-amplitude variability. Several violent outbursts in X-rays and gamma rays have been observed in the past, with intra-night variability in very-high-energy gamma rays (VHE; E > 100 GeV) detected down to the minute...
Dark Matter (DM) particles may either self-annihilate or decay, producing detectable Standard Model (SM) particles, including gamma rays. These processes could lead to excesses in the gamma-ray energy spectra observed on Earth. In this work, we search for those excesses using the Fermi Large Area Telescope (Fermi-LAT) observations of the Milky Way in an energy range from 1 GeV to 1 TeV. We...
The observation of PeVatrons is without doubt one of the major breakthroughs in gamma-ray astronomy. The quest for Galactic cosmic-ray candidates goes hand-in-hand with these discoveries. However, with the advent of the very high-energy observations, many new questions arise. In many of the reported sources the origin of the particles responsible for the gamma-ray is unclear, in many cases...
The Sun is a target of cosmic rays , CR. Their secondary photons by such CR skimming on solar edges, while scattering solar atmosphere and making neutral pions , is one of the expected and partially observed signal. However there are discrepancies in the gamma spectra within the the Sun disk that are not well understood. We first are reconsidering the role of such skimming and scattering CR...
Weakly Interacting Massive Particles (WIMPs) in the GeV-TeV mass range could produce gamma rays through self-annihilation, offering potential observational signatures for indirect dark matter (DM) searches. Dwarf spheroidal galaxies (dSphs) of the Milky Way are prime targets for such studies due to their high inferred DM-induced gamma-ray fluxes and minimal astrophysical background.
In this...
Diffusive shock acceleration (DSA) is a promising acceleration process in a hierarchy of sources, reaching from stellar termination to Galaxy cluster shocks.
Two of the relevant parameters defining the maximal energy reached at the accelerator are the turbulent magnetic field and the shock's lifetime. In this contribution, we show how time-dependent models in complex geometries and diffusion...
In this contribution, we have investigated the energy spectra of the elemental mass groups of cosmic rays for the Light (H+He), medium (C+O) and heavy (Ne-Fe) components using the HAWC observatory. The study was carried out in the energy interval from 10 TeV to 1 PeV using almost 5 years of data on hadronic air showers. The energy spectra were unfolded using the bidimensional distribution of...
The W51 giant cloud is one of the largest star-forming regions in the Galaxy. Several experiments have detected gamma-ray emissions from the W51 complex: Fermi (Jogler and Funk 2016), MAGIC (Aleksic et al. 2012), HESS (H.E.S.S. Collaboration et al. 2018), HAWC (Albert et al. 2020), and more recently, LHAASO (Cao et al. 2024). This complex contains two star-forming regions, known as W51A and...
This presentation describes a demonstration of cosmic ray physics utilizing a pixel detector at the Jungfraujoch Sphinx Observatory. Rates and types of incident radiation are compared at 439m above sea level (CERN) and at 3454m (Jungfraujoch). A MiniPIX TPX3, developed by the CERN Medipix Collaboration, along with default software is utilized for observations. A USB form factor eliminates the...
We present an analysis of the correlation between the depth of the maximum of air-shower profiles and the signal in water-Cherenkov stations in events simultaneously recorded by the fluorescence and surface detectors of the Pierre Auger Observatory. The analysis allows constraints to be placed on the spread of nuclear masses in ultra-high-energy cosmic rays with a minor impact from the...
Understanding cosmic ray variations with latitude and atmospheric conditions is essential for space weather studies and particle physics education. Cosmic Watch (CW), a compact and accessible muon detector, provides a hands-on tool for studying these variations. It consists of a 5 cm × 5 cm × 1 cm plastic scintillator coupled with a silicon photomultiplier to detect scintillation light from...
Most modern studies of Active Galactic Nuclei (AGN) rely on broadband spectral analyses to constrain the plethora of particle acceleration and emission processes. Traditional analysis methods are often hindered by the use of proprietary tools tailored for each participating instrument, making it challenging to integrate multi-wavelength data in a consistent, reproducible[,,] and statistically...
The search for dark matter is advancing into a new era with the development of next-generation gamma-ray observatories, which will significantly enhance detection capabilities. These instruments will extend the limits of detection, offering new opportunities to investigate one of the most elusive components of the universe. Among them, the Southern Wide-field Gamma-ray Observatory, SWGO,...
We report the analysis results in the 2-degree range around G57.2+0.8 by LHAASO using the WCDA data and KM2A data up to July 2024. Compared with other templates, a template with one dust and three additional sources can explain the high-energy gamma-ray emission well in this region. During the processing, the location of the TeV source (TeV J1943+213) was fixed, and the other two fitted...
The new tool that starts to enter all parts of our life is AI – and it enters education as well. There are two large concerns with using AI for education - the safety of students’ data and the AI missing specific knowledge about the given class. The approach of using the Retrieval Augmented Generation provides the user data to the locally run LLM model (using Ollama framework, a free and...
The inner heliosphere, spanning from the solar corona to Earth's orbit, is a dynamic region where energetic particles are accelerated and transported. Understanding these processes is crucial for comprehending space weather phenomena and their impact on Earth. This abstract discusses the key mechanisms involved in particle acceleration near the Sun, primarily driven by solar flares and coronal...
We introduced a parameterization method to analyze the mean muon content $<\ln N_{\mu}>$ and its dispersion $\sigma^{2}(\ln N_{\mu})$ in relation to the mass composition of cosmic-rays. This approach enhances the Heitler model for air showers by employing a parameterization that incorporates the first two moments of the logarithmic mass distribution $\ln A$ and $\sigma^{2}_{\ln A}$. This...
The "Dragonfly" Pulsar Wind Nebula and its surroundings is a complex region with several HE to UHE gamma-ray point-like and diffuse sources accompanied by their multi-wavelength counterparts. MILAGRO discovered the VHE emission in 2012, making it the second brightest MILAGRO source in the northern hemisphere. The region was later resolved into more VHE sources by VERITAS, revealing a complex...
Supernova remnants (SNRs) have been widely believed to be the dominant source of Galactic cosmic rays, which are accelerated up to ~ $10^{15.5}$ eV through the process called Fermi acceleration. However, this paradigm has not been verified, as key aspects of the acceleration process, such as its mechanism and efficiency, are not well understood. Shock velocity is considered as one of the key...
The cosmic ray energy spectrum has always been an important tool for investigating fundamental issues related to origin of cosmic rays. The so-called ”knee” around ∼4 PeV, at where the spectral index changes from-2.7 to-3.1, were observed by several experiments. The measurements of the ”knee” by the ground based experiments still have deviations. Most ground-based experiments measure the...
The Parker Solar Probe (PSP) approaches to the Sun in the past 6 years unveiled a broad variety of Traveling shocks (Ts) in the near-Sun environment, from the very weak Ts that would have been unlikely classified as shocks at 1 AU and are not associated with significant enhancement of energized particles, to the fastest ever Ts in-situ measured in the heliosphere, with unprecedented early-on...
The Alpha Magnetic Spectrometer (AMS) is a precision particle physics detector operating on the International Space Station. Since 2011, AMS has collected more than 250 billion charged cosmic rays, from elementary particles to iron nuclei with energies up to multi-TeV. The high-precision measurements with ~1% accuracy, over a solar cycle, have led to many surprising observations. The latest...
The Earth’s magnetic field acts as a natural spectrometer for cosmic rays. Because the geomagnetic cutoff rigidity varies with geographic location, particles of different energies are selectively filtered depending on their arrival direction and the position of the observer. Space based missions such as the PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics)...
Solar Energetic Particles (SEPs) can be detected in the heliosphere following their acceleration during solar flares and coronal mass ejections (CMEs). They are a key component of the space radiation environment, affecting space weather. SEP observables, including intensity profiles, spectra, composition and anisotropies, carry signatures of the energisation processes and of propagation...
The search for low-energy anti-nuclei in cosmic rays provides a means to test fundamental physics questions, such as the potential existence of primordial antimatter and the nature of Dark Matter.
The “PHeSCAMI” (Pressurized Helium Scintillating Calorimeter for AntiMatter Identification) project aims to explore a novel method for identifying anti-nuclei in cosmic rays. Specifically, when...
Imaging Atmospheric Cherenkov Telescopes (IACTs) are ideal for investigating the nature of moderately extended gamma-ray sources at very high energy thanks to their optimal angular and energy resolution compared to ground array detectors.
The Supernova Remnant SNR G106.3+2.7 is one of the most promising Galactic hadronic PeVatron candidates. We carried out observations using the Large-Sized...
Supernova remnants (SNRs) are often considered as the main sites of acceleration of Galactic cosmic rays, up to the knee feature in the cosmic-ray spectrum. However, their ability to accelerate particles to reach PeV energies is questionable and lacks observational evidence. Theoretical predictions suggest that only a small subclass of very young SNRs evolving in dense environments could...
Relativistic shocks are not efficient cosmic-ray accelerators because after the first shock crossing cycle the particles do not have time to isotropise in the shock upstream region. However, in the first cycle the particles get a boost $\propto \Gamma^2$, where $\Gamma$ is the Lorentz factor of the shock. We construct a model in which particles can achieve ultra-high energies by passing...
We report on the observation of the diffuse cosmic neutrino flux with the Baikal-GVD neutrino telescope. Using cascade-like events collected by Baikal-GVD in 2018–2023, a significant excess of events over the expected atmospheric background is observed. This excess is consistent with the high-energy diffuse cosmic neutrino flux observed by IceCube. The null cosmic flux assumption is rejected...
Galactic PeVatrons are astrophysical sources accelerating particles up to a few PeV (~10^15 eV). The primary method to identify both electron and proton PeVatrons is the observation of gamma-ray radiation at ultra-high energies (UHE, E>100 TeV). In 2021, LHAASO detected 14 steady gamma-ray sources with photon energies above 100 TeV and up to 1.4 PeV. Most of these sources can be plausibly...
The General Anti Particle Spectrometer (GAPS) is a balloon-borne cosmic-ray experiment which prepared to launch in the past Antarctic summer season 24/25.
Its primary science goal is the search for light antinuclei in cosmic rays at kinetic energies below 0.25 GeV/n. This energy region is especially of interest for dark matter searches and is still mostly uncharted.
GAPS promises to yield...
The origin of the highest energy (>100TeV) neutrinos is still highly debated. AGN jets are capable of accelerating hadrons to relativistic speeds, a necessary step for neutrino production in photohadronic processes. A dense photon field, such as UV emission line photons from the broad-line region, can serve as a sufficient target for photohadronic interactions to produce neutrinos. However,...
Galactic $\gamma$-ray sources can be produced by either high-energy protons via proton-proton collisions or electrons/positrons via inverse Compton scattering. Distinguishing between the hadronic and leptonic origin of $\gamma$-ray emission in Galactic sources remains challenging. Measurements of non-thermal X-ray spectra of these sources, which could originate from primary electrons in the...
The wind termination shock of compact star clusters has been recently proposed as a potential site of cosmic ray acceleration. The most recent observation of gamma-ray emission up to a few PeV from Cygnus OB2 by LHAASO indicates that particles can be accelerated up to > 1 PeV in the environment of this star cluster. In this work, we study how a spatially varying diffusion coefficient...
KM3NeT/ARCA is a rapidly evolving neutrino detector in the Mediterranean Sea. The capability of the detector to measure the diffuse astrophysical neutrino flux was recently demonstrated by the observation of an Ultra High Energy neutrino of astrophysical origin. In this contribution an analysis of KM3NeT/ARCA data, employing Machine learning techniques and advanced statistical methods is...
Galactic cosmic rays are widely believed to be accelerated via the diffusive shock acceleration (DSA) mechanism at supernova remnants (SNRs). However, recent observations of SNRs with ages on the order of $10^2$ to $10^3$ years suggest that the maximum energy of accelerated cosmic rays does not reach the PeV scale. In contrast, Inoue et al. (2021) demonstrated through kinetic-MHD simulations...
GRANDProto300 is a pioneering prototype array of the GRAND experiment. It consists of 300 radio antennas and will cover an area of $200\, \text{km}^2$ in a radio-quiet region of western China. Serving as a test bench for the GRAND experiment, GRANDProto300 aims to achieve autonomous radio-detection and reconstruction of highly inclined air showers. It is designed to detect ultra-high-energy...
The origin of cosmic rays (CRs) remains an open question, with their spectrum featuring two key breaks: the knee (~3 PeV) and the ankle (~3 EeV). Ultra-high-energy cosmic rays (UHECRs) above the ankle are widely believed to originate from extragalactic sources, while the transition of galactic to extragalactic CRs occurs between the knee and the ankle. Recent observations suggest that...
IceCube has made measurements of diffuse astrophysical neutrino flux for all flavors up to PeV scales. The high energy (TeV-PeV) IceCube cascade sample is particularly effective at selecting electron and tau neutrinos. We present the results of Single Power Law (SPL) and Broken Power Law (BPL) flux measurements based on 11 years of cascade data. From this cascade sample, we identify high...
Construction of low frequency component (50 - 350 MHz) of the Square Kilometre Array has started in Australia. With an immensely dense core of almost 60 thousand antennas within a square kilometer, the telescope provides a unique opportunity to study cosmic rays in the energy range between the knee and the ankle. High resolution observations and new analysis strategies will provide more...
While much work has gone into associating neutrino emission with various sources, very few sources have emerged. With the recent publication of IceCube Event Catalog (IceCat-1), the IceCube neutrino observatory has released a list of the most promising astrophysical neutrino events since operations began in 2010. Using the archival data from the High Altitude Water Cherenkov (HAWC) gamma-ray...
Cosmic rays (CRs) are among the non-thermal components of the interstellar medium (ISM) that are ubiquitous throughout the Galaxy. While CR number density can be inferred from local measurements on the Earth, their 3D distribution has largely been explored through simulations. A data-driven 3D map of CRs is essential to better understand the spatial distribution of CRs and to probe the...
The Beamforming Elevated Array for COsmic Neutrinos (BEACON) is a detector concept designed to measure the flux of Earth-skimming tau neutrinos above 100 PeV. BEACON will consist of many independent, phased radio arrays placed on mountains. The long in-air propagation length of radio together with the high-elevation sites provide BEACON with a large detector volume in an efficient manner. A...
The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based gamma-ray observatory, designed to enhance sensitivity and energy coverage (20 GeV -- 300 TeV) over current Imaging Atmospheric Cherenkov Telescopes (IACTs). The instrument's specifications will enable detailed Active Galactic Nuclei (AGN) studies in the very-high-energy (VHE) regime. Predicting the AGN...
The detection of the flavor ratio of astrophysical neutrinos provides valuable insight into the neutrino production mechanisms within astrophysical sources and serves as a powerful probe for new physics. Building on the exciting observation of seven tau neutrino candidates by the IceCube experiment in 2024, the TRopIcal DEep-sea Neutrino Telescope (TRIDENT), as a next-generation neutrino...
Relativistic jets play a fundamental role in the phenomenology of black holes and neutron star mergers. I will review briefly the progress made within the EHT collaboration in modelling jet emission from accreting supermassive black holes and their multiwavelength emission. I will also discuss about jet launching from binary neutron star mergers either from a magnetised remnant or from a...
The Telescope Array (TA) experiment has been observing ultrahigh-energy cosmic rays (UHECRs) using a surface detector (SD) array and fluorescence detector (FD) stations since 2008. TA is the largest UHECR observatory in the Northern Hemisphere. It has been expanded by constructing additional SDs and FDs to extend its energy coverage toward both lower and higher energies. These extensions are...
Recent catalogue of the Faraday rotation measures (RM) of extragalactic sources, together with the synchrotron polarisation data from WMAP and Planck, provide us with a wealth of information on the magnetic fields of the Galaxy. We combine several phenomenological components of the GMF –- the spiral arms, the toroidal halo, the X-shaped field, and the field of the Local Bubble –- to construct...
The neutrinos from the core collapse SN1987A are the first extrasolar neutrinos to be ever detected and have been widely studied to infer the thermodynamical and temporal features of a supernova; however their interpretation in terms of the astrophysical properties of the explosion has been giving rise to heated debates since ever. At date, models are still under construction and simulations...
Accretion shocks in the large-scale structure of the universe are promising sources of ultra-high-energy cosmic rays (UHECRs). In addition to accelerating UHECRs, these shocks should produce distinct multimessenger signatures, including synchrotron radio emission, gamma rays, and neutrinos. We investigate how a hierarchical shock acceleration framework—progressing from supernova remnant...
The Fermi and eROSITA bubbles (FBs and eRBs) are the largest gamma-ray and X-ray emitting objects in the sky, respectively. They look like nearly symmetrical pairs of bubbles rising above and below the center of our Galaxy. The FBs extend about $50^\circ$, and their emission mechanism is under debate, whether the leptonic scenario (inverse Compton scattering by relativistic electrons) or the...
The KM3NeT Collaboration is currently building two neutrino detectors at the bottom of the Mediterranean Sea. The KM3NeT/ARCA telescope is under construction off-shore Sicily, Italy, at a depth of about 3.5 km. The main goal of KM3NeT/ARCA is cosmic neutrino studies. KM3NeT/ORCA is being built off-shore Toulon, France, about 2.5 km below the sea surface. Its main physics objective is the...
The transport of cosmic rays (CRs) across galaxy clusters reflects a reciprocal interaction across plasma scales. Large-scale processes (≳kpc) typically influence microscale behavior (~npc), but we show that microscale fluctuations from the mirror instability—inherently patchy and intermittent in nature—shape large-scale radio morphologies in galaxy clusters by mediating CR propagation. Our...
Gamma-ray bursts (GRBs) are one of the main targets for the observations of the MAGIC telescopes. As a result of the effort in improving the sensitivity of the instrument and the automatic follow-up strategy, MAGIC detected two GRBs in the very-high-energy (VHE, E>100 GeV) range, namely GRB 190114C and GRB 201216C. In GRB 190114C ($z=0.42$), the data collected by MAGIC revealed a new emission...
We present results from the High Energy Stereoscopic System (H.E.S.S.) follow-up observations of Gamma-ray Bursts (GRBs) between 2004 and 2019. We are focusing on non-detections and providing the most extensive set of very-high-energy (VHE, >100 GeV) upper limits to date. We use this catalogue to constrain the properties of VHE-detected GRBs and compare them to those detected at VHE. Our study...
KM3NeT/ARCA is a second-generation neutrino telescope currently under construction in the Mediterranean Sea. Its capability to collect high-quality data has been recently demonstrated by the detection of an ultra-high-energy neutrino of astrophysical origin.
Located in the Northern Hemisphere with a high duty cycle, the detector has an optimal view of the Galactic Center, primarily via...
The Unger-Farrar 2023 models of the large scale coherent magnetic field of the Milky Way give comparably good fits to the key constraining data — Faraday rotation measures of extragalactic sources and polarized synchrotron emission -- while maximizing the differences in predictions of UHECR deflections. In this talk we report on our progress in identifying intermediate-scale structures in...
The Radar Echo Telescope (RET) collaboration aims to detect the cosmic neutrino flux at the highest energies through the radar echo method. Radar is a detection technique that allows for determining the position, speed and direction of a macroscopic object using radio waves. In-ice neutrino interactions leave a dense ionization trail that can be detected using radar. We will discuss the very...
The Telescope Array (TA) experiment has reported evidence of an intermediate-scale excess in the arrival directions of ultrahigh-energy cosmic rays (UHECRs) with energies above 57 EeV, known as the TA Hotspot. Initially reported in 2014, this excess continues to be observed with a statistical significance of approximately 3$\sigma$. However, the astrophysical origin of this excess remains...
We present a new model for the TeV afterglow of GRB 221009A. The magnetic acceleration reproduces the rapid increase of the TeV flux in the very early phase. We consider the change in the radial structure of the circumstellar medium from homogeneous to wind-like to describe the breaks in the TeV light curve. Our results imply a highly magnetized ejecta with a significantly thick width, making...
Imaging Atmospheric Cherenkov Telescopes (IACTs), including H.E.S.S., MAGIC, and VERITAS, have detected very-high-energy gamma rays from the central region of the Milky Way. The PeVatron hypothesis posits that the supermassive black hole Sagittarius A* (Sgr A*) accelerates cosmic rays to PeV energies, producing a diffuse gamma-ray emission extending up to tens of TeV across the central...
Measurements of the cosmic-ray electrons plus positrons by several experiments such as CALET, DAMPE and H.E.S.S. have revealed the presence of a spectral break at around 1 TeV whose origin is still unclear. In this contribution, we explore different possibilities for the origin which include an electron source spectrum with a broken power law which is expected from the radiative cooling of...
The Pierre Auger Observatory is the largest air-shower detector in the world, offering unparalleled exposure to photons with energies above $5 \times 10^{16}$ eV.
Since the start of data collection almost two decades ago, numerous searches for photons have been conducted using the detection systems of the Observatory.
These searches have led to the most stringent upper limits on the diffuse...
Gamma-ray emission from the plane of the Milky Way is understood as partly originating from the interaction of cosmic rays with the interstellar medium. The same interaction is expected to produce a corresponding flux of neutrinos. In 2023, IceCube reported the first observation of this galactic neutrino flux, rejecting the null-hypothesis at 4.5σ. The analysis relied on spatial models – based...
Long-duration gamma-ray bursts (GRBs) are produced with ultra-relativistic jets that emerge soon after the collapse of massive stars. The highly variable prompt-emission, lasting for a few minutes, originates from the internal dissipation within the jet. This is followed by afterglow emissions, which can persist for several days. The observed afterglow, from radio to TeV energies, is typically...
We study the propagation of ultra-high-energy cosmic rays (UHECRs) in the local intergalactic magnetic field (IGMF) within a radius of <10 Mpc around the Milky Way. Assuming that the field strength is in the range of 1–3 nG and the correlation length is between 0.01 and 1 Mpc, we demonstrate that the IGMF can not only blur the source image but also shift its position, mimicking the effect of...
Neutrino telescopes are at the forefront of high-energy astrophysics, offering unique insights into some of the most extreme and energetic phenomena in the Universe. The ANTARES detector, which operated for 16 years off the coast of Toulon (France) until 2022, has played a pioneering role in deep-sea neutrino observations. Building upon its legacy, the next-generation KM3NeT-ARCA observatory...
Most ultra-high-energy cosmic rays (UHECRs) are charged particles. As a result, they are deflected by magnetic fields, which can act as lenses, altering their trajectories and (de)magnifying their apparent sources. In this study, we investigate the influence of Galactic magnetic fields on the propagation of UHECRs. The deflections of UHECR trajectories can lead to phenomena such as the...
Recently, precision measurements of cosmic rays have revealed spectral structures that deviate from the previously assumed simple power law. These features offer a wealth of theoretical interpretations to obtain a consistent picture of cosmic ray acceleration, propagation and/or injection, including potential contributions from nearby sources. Among the different species, protons, the most...
This study confronts the Standard Solar Model (SSM) with observed neutrino fluxes (pp, pep, Be7, B8, CNO) by constructing parameterized solar core models (SCMs) with variable helium/metallicity profiles and equilibrium nuclear burning assumptions for pp chains. We find key tension emerges that no SCM simultaneously satisfies all observed neutrino fluxes, notably due to core temperature-driven...
Galactic diffuse gamma-ray emission is the radiation produced by the interaction of high-energy cosmic rays propagating through the Milky Way with the interstellar gas and radiation fields. Its measurement allows for crucial insights into the acceleration and transport of cosmic rays throughout our Galaxy.
Here, we present a new analysis of the TeV Galactic diffuse gamma-ray emission using...
The detection of cosmic-ray antinuclei holds the potential to be a groundbreaking method for identifying signatures of dark matter. The dominant background for cosmic antinuclei arises from interactions of cosmic-ray protons with interstellar hydrogen gas. However, prevalent (anti)nuclei formation models—the thermal and coalescence models—are based on different underlying physics. A deeper...
Over the past decades, there has been growing observational and theoretical evidence that cosmic-ray-induced instabilities play an important role in both acceleration and transport of cosmic rays (CRs). For instance, the efficient acceleration of charged particles in supernova remnant shocks requires rapidly growing instabilities, so much so that none of the proposed processes seem sufficient...
One of the indirect detection method of dark matter (DM) is based on the search of the products of DM annihilation or decay. They should appear as distortions in the gamma rays spectra and in the rare Cosmic Ray (CR) components, like antiprotons, positrons and antideuterons, on top of the standard astrophysical production. In particular, the antiprotons in the Galaxy are mainly of secondary...
The blazar J1048+7143 (a.k.a. J1044+71) is a promising candidate for harboring a supermassive binary black hole (SMBBH) inspiral on the verge of merging. Its gamma-ray, optical, infrared and radio light curves show consistent quasi-periodic oscillations (QPOs) with a period of years. The flares in gamma rays, optical and infrared consist each of two subflares, while in radio, the emission...
Cosmic rays can excite magnetic turbulence via streaming instability as they escape from their sources. The self-generated turbulence is expected to give rise to relatively smaller cosmic-ray diffusion coefficients around these sources than typically inferred for large-scale Galactic transport. In fact, gamma-ray observations from various types of sources including pulsars, stellar clusters...
The High-Energy Particle Detectors (HEPDs) onboard the China Seismo-Electromagnetic Satellite (CSES) mission are designed to study charged particle fluxes in space. The first-generation instrument, HEPD-01 on CSES-01, was originally conceived to measure low-energy electrons and protons but has also demonstrated the ability to detect transient phenomena such as Gamma-Ray Bursts (GRBs). By...
In recent years, neutrino astronomy has rapidly developed. In 2013, the IceCube collaboration announced the detection of an astrophysical neutrino flux. The origin of this flux is still largely unknown. The most promising source candidate is the close-by Seyfert galaxy NGC 1068, with evidence of 4.2 sigma and a soft spectral index.
In 2022 and 2023, two 100 TeV neutrinos, respectively...
The creation of anti-nuclei in the Galaxy has been discussed as a possible signal of exotic production mechanisms such as primordial black hole evaporation or dark matter decay/annihilation in addition to the more conventional production from cosmic-ray interactions. Tentative observations of cosmic-ray andideuteron and antihelium by the AMS-02 collaboration have re-energized the quest to use...
Crystal Eye is a new concept of space-based all sky monitor for the observation of 10 keV - 30 MeV photons exploiting a novel detection technique, which foresees enhanced localization capability and functionality in an unprecedented energy range with respect to the current instruments. This is now possible, thanks to the use of new materials (scintillator crystals) and sensors (like Silicon...
X-ray light curves of gamma-ray burst (GRB) afterglows exhibit various features, with the shallow
decay phase being particularly puzzling. While some studies report absence of the X-ray shallow decay
for hyper-energetic GRBs, recently discovered GRB 240529A shows a clear shallow decay phase with
an isotropic gamma-ray energy of $2.2\times10^{54}$ erg, making it a highly unusual case...
Active galactic nuclei are promising candidates for astrophysical neutrino sources, as suggested by the detection of a high-energy neutrino positionally consistent with the flaring blazar TXS 0506+056 and evidence of neutrino emission from the nearby Seyfert galaxy NGC 1068. Our recent studies based on the IceCube time-integrated sky maps provided evidence of a statistically significant...
Recent secondary-over-primary cosmic-ray (CR) ratio measurements by DAMPE and CALET show a hint of a flattening above ( \sim) TV rigidities. It is plausible - and theoretically well-motivated - that CRs accumulate additional grammage inside the source environment leading to a constant grammage in addition to the Galactic one. In this contribution, we explore this scenario, quantifying the...
The Pacific-Ocean Neutrino Experiment (P-ONE) is a new neutrino telescope that is currently under construction in the North Pacific Ocean. The future location of the detector is the Cascadia Basin, a flat 2660 m deep region of ocean off the coast of Vancouver Island, Canada. P-ONE will be made up of one kilometre long strings of optical instrumentation. The collaboration is currently working...
We conduct 1D particle-in-cell (PIC) and particle-in-cell-magnetohydrodynamic simulations of a hot superAlfvénic electron-positron (ee) beam pervading a cold electron-proton (ep) background. We investigate the growth and saturation of the resonant streaming instability triggered by the ee beam. We confirm quasi-linear growth rates and a saturated amplitude of waves to be consistent with a...
Out in the universe, when ultra-high energy charged cosmic rays (UHECR) propagate from their source and/or acceleration site, they may interact with the environment (gas), producing high-energy gamma rays and neutrinos. One of the main uncertainties in the prediction of the flux of gamma rays and neutrinos from such UHECR interactions is due to the uncertainties in the modeling of hadronic...
Cosmic rays (CRs) play crucial roles in various astrophysical environments in the present Universe. They can penetrate deep into dense molecular clouds, altering their ionization degree and influencing star formation. Additionally, CRs exert pressure on galactic gas and contribute to driving galactic winds. However, their role in the early Universe remains poorly understood. Since CRs are...
The recent detection of very high-energy (VHE, $>$ 100 GeV) gamma-ray emission from gamma-ray bursts (GRBs) has provided new insights into afterglow physics. Understanding the temporal and spectral evolution of VHE GRBs requires detailed modeling and multi-wavelength observations spanning radio to VHE. The afterglow emission primarily consists of synchrotron radiation from forward and reverse...
KM3NeT/ARCA is a large underwater Cherenkov neutrino detector, currently under construction at the bottom of the Mediterranean Sea. The detector geometry is optimised for the observation of TeV-PeV astrophysical neutrinos. Once completed, the detector will consist of 230 Detection Units (DUs). A Detection Unit is an 800-meter vertical line that holds 18 Digital Optical Modules, containing 31...
Recently, LHAASO has announced the highest-energy measurements of the diffusive gamma-ray flux, offering the possibility of probing the spatial distribution and energy spectrum of the galactic cosmic rays (CRs) up to the all-particle spectrum knee ($\sim 4$ PeV). However, a persistent tension between observations by experiments (such as Fermi and LHAASO) and the predictions based on...
Antiprotons and antideuterons in cosmic rays (CRs) are studied to search for potential signals of exotic physics—such as dark matter annihilation—beyond the expected astrophysical background produced by collisions between primary CRs and the interstellar medium.
In particular, it has been argued that the production of secondary antideuterons should be suppressed at kinetic energies below a...
The TeV gamma-ray band is essential for probing the most extreme particle acceleration processes in the Universe. The recent detections of gamma-ray bursts (GRBs) at these energies offer an incredible opportunity to investigate the origins of such transient events in an unprecedented way. In this presentation, we analyze the afterglows of these GRBs by modeling their synchrotron and inverse...
Multimessenger observations, combining electromagnetic radiation and neutrinos, offer critical insights into the high-energy processes occurring in astrophysical sources. Recent coincident detections of high-energy neutrinos from the direction of blazars highlight them as ideal candidates for multimessenger modeling, and at the same time underscore the necessity of accurate modeling frameworks...
High-precision cosmic ray measurements from both space-based and balloon-borne experiments have revealed a variety of spectral features. Primary nuclei and their secondaries produced during propagation exhibit spectral hardening above $\sim$200 GV. Proton-spectrum softening has been observed at $\sim$10 TeV. Helium-spectrum softening has been observed at slightly higher energies. A positron...
As of early 2025, the GRAND collaboration has three prototype arrays in operation: GRANDProto300 in China, GRAND@Nançay in France, and GRAND@Auger in Argentina.The GRAND@Auger prototype was established through a collaboration between the GRAND and Pierre Auger Observatories, repurposing ten Auger Engineering Radio Array (AERA) stations into GRAND detection units. This setup provides a unique...
Cosmic rays (CRs) interact with turbulent magnetic fields in the interstellar medium (ISM), generating non-thermal emission. Recent ultra-high-energy gamma-ray (UHEGR) observations by LHAASO, linked to star-forming regions in the ISM, have introduced new challenges in understanding CR acceleration and propagation in these environments. Despite decades of study, the diffusion of CRs within the...
Diffuse emission in gamma-rays and neutrinos are produced by the interaction of cosmic rays with the interstellar medium. Below some hundreds of TeV, the sources of these cosmic rays are most likely Galactic. Hence, observations of high-energy gamma-rays and neutrinos can be used to probe the flux of cosmic rays in other parts of the Galaxy. Supernova remnants are usually considered as the...
The origin of Fast Radio Bursts (FRBs) remains a longstanding and intriguing mystery. Discovering their progenitors will increase our knowledge of compact objects in extreme environments and will improve the use of these sources to probe cosmology and the structure of galaxies. A key discriminator between various models is the presence of multiwavelength counterparts. Although previous...
KM3NeT/ARCA is a Cherenkov neutrino telescope currently under construction in the Mediterranean Sea, at 100 km off the Sicilian coast, near Capo Passero, and at about 3500 m depth.
On its final configuration, the detector will consist of a cubic kilometer volume of seawater instrumented with light detectors. Now, 33 detector units have been already deployed and are taking data. In this...
The Payload for Ultrahigh Energy Observations (PUEO) is slated to fly in December of this year out of McMurdo Station in Antarctica in search of the highest energy neutrinos produced in our Universe. PUEO is designed to detect Askaryan emission, a broadband radio signal that occurs when a neutrino interacts in a dense dielectric medium like Antarctic ice. To achieve better sensitivity than...
The collapse of the core of a massive star at the end of its life can give rise to one of the most powerful phenomena in the Universe. Because of violent mass motions that take place during the explosion, Core Collapse Supernovae have been considered a potential source of detectable gravitational waveforms for decades. However, their intrinsic stochasticity makes almost impossible modeling and...
Fast Radio Bursts (FRBs) are brief, highly energetic radio flashes of unknown origin. Their high luminosity, short duration, and large dispersion measures suggest an extragalactic origin, potentially linked to extreme astrophysical objects such as magnetars. The growing number of detected FRBs, including repeating sources, has driven extensive multi-wavelength follow-up efforts. While FRB...
The recent detection of a multi-PeV neutrino event by KM3NeT/ARCA opens a new window into the origins of ultra-high-energy cosmic rays (UHECRs). We revise the possibility of a cosmogenic origin for this event while considering constraints from the diffuse extragalactic gamma-ray background (EGRB) observed by Fermi-LAT and the non-detection of ultra-high-energy (UHE) photons ($\gtrsim$ EeV) by...
IceCube has detected a diffuse flux of high energy neutrinos, with the only two high-confidence extragalactic sources identified to-date being the accreting supermassive black holes (SMBHs) TXS0506+056 and NGC1068. This suggests that other SMBHs may also contribute to the observed neutrino flux. It is possible that some fraction of the IceCube neutrinos originate in time-variable SMBH...
The spatial diffusion of energetic particles in a magnetic field composed of a large-scale background and a small-scale turbulent component should be expected to be anisotropic. While such anisotropic diffusion has been known for quite a while in first-principle plasma physics and while it is required for an understanding of the transport of cosmic rays in the heliosphere or close to supernova...
The ISS-based Calorimetric Electron Telescope (CALET) is directly measuring the energy spectrum and direction distribution of electron+positron cosmic-rays up to 20 TeV. The electron+positron events measured by CALET have been analyzed for a possible dipole anisotropy, which could be a signature of nearby SNR such as Vela.
The methods used to derive limits on the anisotropy from the...
Galactic diffuse gamma-rays emission (GDE) in the sub-PeV energy range (E > 100 TeV = $10^{14}$ eV) was first detected by the Tibet AS$\gamma$ experiment in 2021, ensuring the presence of PeV cosmic-ray accelerators in the Galaxy. On the other hand, in 2023 the Large High Altitude Air Shower Observatory (LHAASO) detected GDE covering an energy range between 10 TeV and 1 PeV. Interestingly, the...
The origin of ultra-high-energy cosmic rays (UHECRs) is still an elusive question, mainly because the arrival directions do not point to a preferred source location. However, it has recently been observed that the amplitude of the dipole anisotropy detected by the Pierre Auger Observatory increases with the energy. This can be interpreted as an indication of the presence of a dominant source...
The cosmic-ray(CR) electrons and positrons are of great significance for studying the origin and propagation of cosmic-rays. The satellite-borne experiment DArk Matter Particle Explorer(DAMPE) has been used to measure the separate electron and positron spectra, as well as the positron fraction. In this work, the Earth's magnetic field is used to distinguish CR electrons and positrons, as the...
The IceCube Neutrino Observatory searches for the origins of astrophysical neutrinos using various techniques to overcome the significant backgrounds produced by cosmic-ray air showers. One such technique involves combining the neutrino data with other cosmic messengers to identify spatial and temporal correlations. IceCube contributes to multi-messenger astrophysics by providing alerts for...
The next generation neutrino telescope, IceCube-Gen2, will be sensitive to the astrophysical and cosmogenic flux of neutrinos across a broad energy range, from the TeV to the EeV scale. The planned design includes 8 cubic kilometers of ice instrumented with approximately 10,000 optical sensors, a surface array, and a radio array of antennas embedded in the ice laid out sparsely over 500 km^2....
Gamma-ray bursts (GRBs) are bright flashes of electromagnetic radiation originating from the core collapse of massive stars or the merger of compact objects. It has long been theorized that GRBs can emit very high-energy (VHE) gamma rays that can reach the TeV level. Although current-generation Imaging Atmospheric Cherenkov Telescopes (IACTs), such as H.E.S.S., have been observing GRBs since...
The IceCube Neutrino Observatory issues real-time high-energy neutrino alerts and has released its first catalog (IceCat-1). However, the origin of these high-energy neutrinos remains largely unknown. Active galactic nuclei (AGNs) with variability are promising candidate sources. Previous studies have suggested a temporal correlation between high-energy neutrino alerts and infrared flares. In...
The IceCube Neutrino Observatory actively participates in multi-messenger follow-ups of gravitational-wave (GW) events. With the release of the Gravitational-Wave Transient Catalog (GWTC)-2.1 and -3, the sub-threshold GW event information from the third observation run of the LIGO-Virgo-KAGRA (LVK) detectors is publicly available. These sub-threshold GWs are identified via template-based and...
Over the last decade, highly accurate high-energy cosmic-ray electron energy spectra have been obtained with superior instruments such as CALET. Their energy spectra, which show characteristic structures, have the potential to unveil the origin of cosmic-ray electrons whose most likely candidates are supernova remnants (SNRs). In this work, we estimate the intragalactic temporal and spatial...
Galactic diffuse gamma-ray emissions have been observed from MeV to PeV energies.
These emissions are connected via a common origin of the cosmic ray (CR) particles, but the energy dependence and hadronic/leptonic fraction remain unconstrained.
We model the Galactic CR distributions and associated non-thermal diffuse emissions from TeV--PeV energies using the GALPROP framework.
We...
POEMMA-Balloon with Radio (PBR) is a scaled-down version of the Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) design, optimized to be flown as a payload on one of NASA's sub-orbital super pressure balloons circling over the southern oceans for a mission duration of as long as 50 days. One of the main science objectives of PBR is to follow up astrophysical event alerts in search for...
Gamma-ray bursts (GRBs) are the most powerful transient explosions in the Universe and emit a vast amount of their energy in the form of gamma-rays. Although they last extremely short on cosmic time scales, their gamma-ray emission shows a wealth of temporal variability. Properties of this variability may carry information about the processes the gamma-rays emerge from, which remain poorly...
Despite all that we have learned from observational data, the sources of ultra-high-energy cosmic rays (UHECRs) have not yet been identified. Among the candidates discussed in the literature, starburst galaxies and active galactic nuclei (AGNs) are likely the most popular. Studies from the Pierre Auger Observatory indicate that the mass composition of particles with energies above $10^{19.3}$...
Gamma-ray bursts (GRBs) originate from explosions at cosmological distances, generating collimated jets. GRB 221009A, triggered on 9 October 2022, has been established as the brightest GRB to date. Its bright and long emission was extensively followed up from radio to gamma rays. LHAASO firmly detected the onset of the afterglow emission at energies up to ~13 TeV within about an hour after the...
The widely anticipated outburst of recurrent nova T Coronae Borealis (T CrB), which is near the end of its 80-year cycle, provides an excellent opportunity to search for neutrinos from novae. Novae are an energetic class of transients, which have been studied for hundreds of years. Because many of them are located nearby, novae provide an excellent astrophysical laboratory to study...
Traditional searches for neutrino point sources have been hindered by the look-elsewhere effect. To address this, TAMBO will generate a catalog of neutrino source localizations - each localization equivalent in size to the square of TAMBO’s angular resolution. In doing so, TAMBO will have significantly reduced the available space to be searched by neutrino observatories, thus decreasing the...
Recently, IceCube has observed an excess of astrophysical neutrinos from the Galactic plane. Such a signal may indicate the presence of individual sources or a diffuse neutrino flux from the interactions of local hadronic cosmic rays. We consider the prospect of neutrino production in galactic X-ray binary systems. A model for neutrino production in the variable jets of these systems is...
The detection of transient phenomena such as Gamma-Ray Bursts (GRBs), Fast Radio Bursts (FRBs), stellar flares, novae, and supernovae—alongside novel cosmic messengers like high-energy neutrinos and gravitational waves—has transformed astrophysics in recent years. Maximizing the discovery potential of multi-messenger and multi-wavelength follow-up observations, as well as serendipitous...
Various models were proposed to explain the observed spectrum and composition of ultra-high-energy cosmic rays (UHECRs), but they remain inconclusive in constraining their source of origin. A significant neutrino event with an estimated energy between 72 PeV and 2.6 EeV was recently observed by the KM3NeT experiment (henceforth referred to as KM3-230213A). When interpreted as cosmogenic in...
The recent detections of the afterglow phase of long gamma-ray bursts (lGRBs) at very high energies (VHE, >100 GeV) mark a significant advance in astrophysics of transient phenomena, offering deeper insights into the acceleration mechanisms, jet structure, and physical processes driving GRB emission. In the multi-messenger landscape, both high-energy neutrino and gravitational-wave detections...
The first deep images with the James Webb Space Telescope (JWST) have transformed our view of the Universe. From day one, JWST produced one surprise after another: from unexpectedly luminous candidate galaxies at z>10, to an abundant, new class of obscured black holes, to massive quiescent galaxies when the Universe was only 1-2 Gyr old. With its unparalleled imaging and spectroscopic...
The IceCube neutrino observatory has been successfully operating in its full configuration for almost 15 years and is characterized by a remarkably high stability and uptime. During this time, it has made many groundbreaking observations, such as the first detection of a high-energy diffuse cosmic neutrino flux or, more recently, the identification of the AGN NGC1068 as a steady source of...
How magnetized turbulent plasmas can accelerate charged particles is a long-standing question dating back to the seminal work of Enrico Fermi in the late 1940s. Nowadays, it is often invoked to model the production of non-thermal particle spectra in a variety of astrophysical settings, including extreme, relativistic sources such as black hole accretion disks, pulsar wind nebulae, or...
Axions and ALPs are amongst the prime candidates for dark matter. Consequently there is a broad effort aiming for their detection. However, it is also worthwhile what we can learn beyond an initial detection. Can we establish whether it is a QCD axion and whether it consitutes most of the dark matter in the Universe? Can it serve as a probe for deep UV physics?
The quest to uncover the nature of dark matter remains one of the central goals in astroparticle physics. A leading hypothesis is that dark matter is composed of new elementary particles, with possible masses and interaction cross sections spanning many orders of magnitude. Particles in the MeV to TeV mass range may leave observable signatures through rare scatters off atomic nuclei or...
The discovery of the first astrophysical sources of high-energy neutrinos by IceCube jump-started high-energy neutrino astronomy. To advance the field, we must increase the number of identified sources from a few to dozens. However, progress is currently limited by the relatively low detection rate of astrophysical neutrinos and restricted sky coverage of IceCube, the single kilometer-scale...
The detections of rare events above 5 PeV by two neutrino telescopes highlights the existence of a neutrino flux at these energies. In over a decade of data taken by the IceCube Neutrino Observatory, three events were detected and reconstructed to have energies above 5 PeV. More recently, the KM3NeT neutrino telescope announced their detection of a possible O(100 PeV) neutrino candidate. The...
The JEM-EUSO (Joint Exploratory Missions for Extreme Universe Space Observatory) collaboration is an international initiative studying ultra-high-energy cosmic rays (UHECRs) and related phenomena. These particles, with energies exceeding 10$^{20}$ eV, provide insights into extreme astrophysical processes but remain challenging to detect due to their low flux.
At the heart of JEM-EUSO's...
When the Peccei-Quinn symmetry breaks after inflation, domain walls will form at the QCD scale in the axion field if there is more than one quark charged under the symmetry (as in e.g. the DFSZ model). When destabilised by quantum gravity effects, the collapse of the wall network creates relativistic axions, which subsequently turn non-relativistic and contribute to cold dark matter....
The DArk Matter Particle Explorer (DAMPE) is a space-borne experiment that indirectly searches for dark matter by measuring the high-energy cosmic ray electrons/positrons (CREs) and gamma rays. The key sub-detector of DAMPE is the Electromagnetic CALorimeter (ECAL), which is designed for precise energy measurement with a large dynamic range from 5 GeV to 10 TeV. The ECAL consists of 308...
Neutrino telescopes play a key role in multi-messenger astrophysics, providing unique insights into the still-unclear processes in our Universe and its active sources.
With the goal of shedding light on these mysteries, the KM3NeT collaboration is deploying a deep-sea Cherenkov neutrino telescope in the Mediterranean Sea.
It comprehends two detectors: identical in their design but...
The Cosmic Ray Energetics and Mass for the International Space Station (ISS-CREAM) is designed to directly measure the energy spectra of high-energy cosmic rays, ranging from protons to iron nuclei, over the energy range of $\sim$$10^{12}$ to $\sim$$10^{15}$ eV. The goal of the instrument is to probe the origin, propagation and acceleration mechanisms of cosmic rays. The instrument comprises...
Axion-like particles (ALPs) are hypothetical pseudoscalar particles predicted in several extensions of the Standard Model. These particles have the potential to address both the dark matter problem and the strong CP problem. One method to detect ALPs is through the phenomenon of ALP-photon oscillation in the presence of magnetic fields. In high-energy astrophysics, ALP-photon oscillation can...
Galaxy clusters are the most massive gravitationally bound structures in the Universe. Even if clusters are nearly virialized structures, they undergo merging processes, creating merging shocks, and suffer from feedback from galaxies and AGNs; causing complex turbulent motions and amplifying their magnetic fields. These processes act as acceleration mechanisms for the plasma of the...
In this talk, we report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (360 kyr) pulsar J1846+0919 with LHAASO. The source is detected with a significance of 7 σ for E>10 TeV assuming a Gaussian template. The best-fit position is (RA, Dec) = 281°.90±0°.21, 9°.44±0°.17, and the extension is 0°.88±0°.17. The spectrum can be described...
In this contribution, we present a search for dark matter signatures from the Virgo Cluster using over 200 hours of observations with the H.E.S.S. Imaging Atmospheric Cherenkov Telescope Array. Galaxy clusters provide an ideal environment for investigating potential dark matter interactions, whether through particle decay or annihilation, which could generate a persistent flux of...
Short gamma-ray bursts (GRBs) are some of the brightest transients in the universe. Heavy axion-like particles (ALPs) can be produced in the hot plasma of GRB fireballs and escape, transporting energy away the from the source. When they decay outside the source, we show that the resulting photon field is too rarefied to re-thermalize, effectively preventing the re-emergence of the fireball,...
Geminga is the first pulsar around which a remarkable TeV gamma-ray halo extending over a few degrees was discovered by MILAGRO, HAWC and later by H.E.S.S., and by Fermi-LAT in the GeV band. Similar emission has been detected for other middle-aged pulsars in their late evolution stages, and is most plausibly explained by inverse Compton scattering of CMB and interstellar photons by...
We report the GeoMagFilter database for modeling the angular-rigidity joint distribution of galactic cosmic rays on low Earth orbit caused by the shielding of geomagnetic field and the Earth atmosphere. We use a backtracing software which integrates the particle trajectory with eight order Runge-Kutta algorithm in the geomagnetic field described by the IGRF13 model. At every 10 degree in...
The blazar 3C 454.3 experienced a major flare in November 2010 making it the brightest $\gamma$-ray source in the sky of the Fermi-LAT. Motivated by the $3\sigma$ association of a $\gtrsim 290$ TeV muon neutrino IceCube170922A with an electromagnetic flare in TXS 0506+056 and noting that 3C 454.3 was $\sim 100$ times brighter than TXS 0506+056, we enquire what level of the neutrino flux we...
The cosmic background (CB) is defined as the isotropic diffuse radiation field with extragalactic origin found across the electromagnetic spectrum. Different astrophysical sources dominate the CB emission at different energies, such as stars in the optical or active galactic nuclei in x rays. Assuming that dark matter consists of axions or axionlike particles with masses on the order of...
The POEMMA-Balloon with Radio (PBR) is a Ultra Long Duration Balloon payload scheduled for launch in Spring 2027 from Wanaka, New Zealand. It will circle over the Southern Ocean for a mission duration as long as 50 days, serving as a precursor to the dual satellite mission, Probe of Extreme Multi-Messenger Astrophysics (POEMMA). The PBR mission represents a significant step towards...
Pulsar halos are a recently identified class of TeV γ-ray sources, offering valuable insights into the evolution of pulsar systems at the highest energies. However, only a handful of such sources have been detected so far, making each new identification critical for understanding the properties of the population as a whole. We report the first detection of extended very-high-energy (VHE) γ-ray...
A major fraction of gamma-ray sources in the non-thermal universe are pulsar wind nebulae (PWNe), which evolve rapidly and exhibit distinct morphological and spectral features at different evolutionary stages. LHAASO has identified dozens of TeV sources associated with pulsars, which are potential candidates for PWNe or halos. In this study, we use LHAASO data to investigate the relationship...
Blazars have emerged as prominent sources of high-energy neutrinos, with multiple IceCube events linked to them in recent years. A growing body of observational evidence suggests that relativistic beaming is a crucial factor in neutrino emission from these extreme astrophysical accelerators. In this work, we conduct a statistical investigation of this connection by analyzing jet geometry,...
We present preliminary results for IceCat-2, the second public catalog of IceCat Alert Tracks, which plans to build and improve upon the first release, IceCat-1. The initial catalog included all real-time alerts issued since 2016, as well as events observed by IceCube since the start of full-detector data collection in 2011 that would have triggered an alert if the program had been in place at...
The Terzina payload on board the NUSES space mission is being built in collaboration with TAS-I by GSSI, INFN and the University of Geneva. It is a Cherenkov Schmidt-Cassegrain compact telescope with effective focal length of 925 m and a camera focal assembly composed of 640 pixels (16 vertically x 40 horizontally) organized in 8x8 tiles produced by FBK with sensitive area 2.73 x 2.34...
We present results over an 11-year Solar cycle of cosmic antiprotons in the rigidity range from 1.00 to 41.9 GV. The antiproton fluxes exhibit distinct properties. Compared with other cosmic elementary particle fluxes (proton, electron, and positron), the magnitude of the antiproton flux temporal variation is significantly smaller. A hysteresis between the antiproton fluxes and the proton...
Blazars are promising candidates for astrophysical neutrino sources. Multi-messenger lepto-hadronic models based on proton–photon ($p\gamma$) interactions predict spectra that peak at high energies, whereas statistical searches often assume a power-law shape, emphasising lower energies. We investigate how these spectral assumptions impact neutrino--blazar associations by incorporating...
The presence of slow diffusion regions as a possible explanation for extended TeV emission around pulsars such as Geminga, Monogem, and PSR J0622+3749, as well as for the X-ray filaments surrounding bow shock pulsar wind nebulae like the Guitar Nebula, PSR J2030+4415, and the Lighthouse Nebula, challenges the conventional understanding of the cosmic ray diffusion coefficient in the...
In this work, we investigate the Oscillating Asymmetric Dark Matter (OADM) model as a potential solution to the core-cusp problem, a well-known discrepancy between the predictions of the ΛCDM (Lambda Cold Dark Matter) cosmological model and the observed dark matter density profiles in dwarf spheroidal galaxies. While ΛCDM simulations typically predict a steep, cusp-like increase in dark matter...
The detection by the KM3NeT experiment of the ultra-high-energy event KM3-230213A marks a milestone in neutrino astrophysics. With an energy estimated at ~ 220 PeV, it is the most energetic cosmic neutrino observed to date, opening the question of its astrophysical origin. Blazars, among the most powerful cosmic accelerators, have been proposed as promising sources of both astrophysical...
Star-forming galaxies (SFGs) are considered to be an important component of the diffuse extragalactic gamma-ray background (EGB) radiation observed in 0.1 -- 820 GeV, but their quantitative contribution has not yet been precisely determined. In this study, we aim to provide the currently most reliable estimate of the contribution of SFGs based on careful calibration with $\gamma$-ray...
A number of studies assert that dark matter (DM) subhaloes without a baryonic counterpart and with an inner cusp always survive no matter the strength of the tidal force they undergo.
In this work, we perform a suite of numerical simulations specifically designed to analyse the evolution of the circular velocity peaks ($V_\mathrm{max}$, and its radial value $r_\mathrm{max}$) of low-mass DM...
In our recent paper, we demonstrated that the luminosity ratios of neutrinos and unabsorbed hard X-rays from the blazars TXS 0506+056 and GB6 J1542+6129 are consistent with neutrino production in a γ-ray obscured region near a central supermassive black hole. The X-ray flux appears to arise from reprocessed γ-ray emission with a flux comparable to that of the neutrinos. Similar neutrino–hard...
More than a decade ago, the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope unveiled the existence of two gigantic gamma-ray lobes known as the Fermi bubbles. While their origin is still unknown, various studies identified intricate spectral and morphological structures within the bubbles. One peculiar region, the cocoon, has recently been associated with gamma-ray...
Cosmic rays inside the heliosphere interact with the solar wind and with the interplanetary magnetic field, resulting in a temporal variation of the cosmic ray intensity near Earth for rigidities up to a few tens of GV. Previous AMS results on proton and helium spectra showed that the two fluxes behave differently in time. In this contribution, the precision results of the light ions up to...
On February 13, 2023, the KM3NeT/ARCA neutrino telescope detected an ultra-high-energy neutrino event, KM3-230213A, with an estimated energy of approximately 220 PeV — the most energetic neutrino ever observed. This unprecedented event marks a significant milestone in the field of astroparticle physics, offering new insights into the potential sources of these extreme astrophysical...
The IceCube Neutrino Observatory has detected evidence for TeV neutrinos from NGC 1068, a nearby Seyfert II galaxy. This discovery suggests that active galactic nuclei (AGN) may play a significant role as sources of high-energy astrophysical neutrinos. Interestingly, the absence of the expected TeV gamma-ray flux indicates that these gamma-rays could be effectively obscured at their production...
On February 13th, 2023, the KM3NeT/ARCA telescope detected a neutrino candidate with an estimated energy in the hundreds of PeVs. We review the observation of this ultra-high-energy neutrino in light of observations above tens of PeV from the IceCube and Pierre Auger observatories. Furthermore, we discuss how the ultra-high-energy data were fit together with the IceCube measurements at lower...
Recent observations of a variety of ionization tracers have revealed an unexpectedly high ionization rate in the Central Molecular Zone (CMZ), that cannot be explained by ionization of cosmic rays. The current observations point to a source of particles that is very concentrated around the Galactic Center and should emit low energy ionizing particles (to avoid propagating too far away from the...
We investigate ultra-fast outflows (UFOs) in active galactic nuclei (AGN) as potential sources of ultra-high-energy cosmic rays (UHECRs), focusing on cosmic-ray nuclei, an aspect not explored previously. These large-scale, mildly-relativistic outflows are a common feature of AGN. We study the cosmic-ray spectrum and maximum energy attainable in these environments with 3D CRPropa simulations...
IceCube recently reported evidence for TeV neutrino emission from several nearby Seyfert galaxies, with the highest significance found for NGC 1068. The absence of TeV gamma rays suggests neutrino production in the AGN corona, which is opaque to high-energy photons. Assuming stochastic proton acceleration, we model the neutrino emission of a Seyfert galaxy as a function of its intrinsic X-ray...
The gravitationally lensed blazar PKS 1830-211 underwent a historically bright and unusually long-duration gamma-ray flaring episode in 2019/2021 with daily fluxes exceeding > $10^{-6}$ ph/cm$^2$/s for ~400 days, and daily peak fluxes (> $10^{-5}$ ph/cm$^2$/s) exceeding all prior flares observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope in the first 15...
Circumstantial evidence points to binary neutron star (BNS) mergers as the principal source of ultrahigh energy cosmic rays (UCRs), as will be briefly reviewed. This motivates trying to predict consequences of the BNS merger scenario for the UCR spectrum and composition, and also multi-messenger implications in particular gravitational wave-EHE neutrino coincidences. In this talk I will
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We present the precision measurements of daily cosmic electron fluxes in the rigidity range from 1.00 to 41.9 GV with 13.5 years data collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station from May 2011 to November 2024. The electron fluxes exhibit variations on multiple time scales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and...
Precision measurements by AMS reveal unique properties of cosmic charged elementary particles. In the absolute rigidity range ~60 to ~500 GV, the antiproton flux and proton flux have nearly identical rigidity dependence. This behavior indicates an excess of high energy antiprotons compared with secondary antiprotons produced from the collision of cosmic rays. More importantly, from ~60 to ~500...
The recent discovery of multi-TeV pulsed emission from Vela and PSR J1509-5850 represents a major breakthrough in pulsar physics. We present the latest findings from very high-energy (VHE) observations using the H.E.S.S. telescopes and discuss key similarities and differences in the emission properties of these two pulsars in the GeV and multi-TeV ranges, in relation to their main...
In standard $\Lambda$CDM cosmology, dark matter (DM) halos are teeming with numerous substructure, or subhalos, as a natural consequence of the way structure formation works in $\Lambda$CDM. If massive enough, both halos and subhalos host visible galaxies, while lighter ones would host no stars or gas at all and would remain dark (dark satellites). In this work, we have used Auriga - a set of...
We investigate the propagation of ultraheavy (UH) nuclei as ultrahigh-energy cosmic rays (UHECRs). We show that their energy loss lengths at $\lesssim300$~EeV are significantly longer than those of protons and intermediate-mass nuclei, and that the highest-energy cosmic rays with energies beyond $\sim100$~EeV, including the Amaterasu particle, may originate from such UH-UHECRs. We derive...
The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) mission launched from Wanaka New Zealand on May 13 2023. The onboard Cherenkov Telescope (CT) was pointed just below Earth's horizon to conduct Target of Opportunity (ToO) observations, in order to follow up on possible sources of >10PeV neutrinos. For these observations, the earth is used as a tau-neutrino to...
The Pacific Ocean Neutrino Experiment (P-ONE) is a cubic-kilometer scale neutrino telescope to be deployed in the northern Pacific Ocean off the West Coast of Canada. P-ONE will observe high-energy neutrinos using an array of kilometer tall mooring lines instrumented with P-ONE Optical Modules (P-OMs) which detect Cherenkov light from neutrino-induced secondary particles within the detector...
Ultra-high-energy cosmic rays (UHECRs) have long been assumed to entirely consist of iron and/or lighter atomic nuclei, and this assumption has been hard-coded in a great deal of software for UHECR simulations and data analysis. However, in the last few years several authors have started questioning this assumption and entertaining the possibility that UHECRs might at least partly consist of...
The development of next-generation cosmic-ray spectrometers requires a robust technological foundation to enable precise and high-sensitivity measurements. This work explores the technological advancements in superconducting magnets and pixel silicon-based trackers, focusing on their application in balloon-borne demonstrators as testbeds for future space missions. Balloon experiments offer a...
The Tibet AS$\gamma$ experiment, observing cosmic rays/gamma rays above a few TeV, is located at 4,300 m above sea level, in Tibet, China. The experiment is composed of a 65,700 m$^{2}$ surface air shower array and 3,400 m$^{2}$ underground water Cherenkov muon detectors. The surface air shower array is used for reconstructing the primary particle energy and direction, while the underground...
The IceCube Neutrino Observatory utilizes the Cherenkov radiation emitted by charged secondary particles produced in interactions of neutrinos with ice nucleons to detect neutrino events. “Starting events”, where this interaction vertex is contained inside the detector volume, can be used to distinguish neutrinos from the dominant background of atmospheric through-going muons. We present the...
Non-jetted AGN exhibit hard X-ray emission with a power law spectrum above $\sim$2 keV, which is thought to be produced through Comptonization of soft photons by electrons and positrons (pairs) in the vicinity of the black hole. The origin and composition of this plasma source, known as the corona, is a matter open for debate.
Our study focuses on the role of relativistic protons accelerated...
The nature of Dark Matter is one of the important unresolved questions in fundamental physics. It is assumed in many Beyond Standard Model theories that dark matter candidates can have weak coupling to Standard Model (SM) particles. In heavy cosmological objects, like galaxies, the Sun, or the Earth, dark matter can be gravitationally accumulated in high abundance. Then, the DM can decay or...
The High Altitude Water Cherenkov (HAWC) Observatory has identified three TeV gamma-ray sources in the DA 495 region, a complex area of the Galactic plane that includes the pulsar wind nebula candidate DA 495 and other sources. In this talk, I will present an updated analysis of the morphology and energy spectra of these sources using 2860 days of HAWC data processed with an improved...
The IceCube Neutrino Observatory at the South Pole detects neutrinos from the entire sky, both of astrophysical and atmospheric origin, via the Cherenkov light emitted when these neutrinos interact in the ice, giving rise to rapidly moving charged particles. Neutrino events with vertices contained within the detector volume are useful for studying the neutrino flavor ratio, as they allow for a...
This presentation covers recent results from the joint analysis of neutrino and electromagnetic cascade emissions from neutrino-coincident tidal disruption events (TDEs), using both an isotropic wind model and relativistic jets. We discuss constraints from Fermi gamma-ray upper limits on the size of the radiation zone and on the maximum energies of accelerated cosmic rays, and the resulting...
Weakly Interacting Massive Particles (WIMPs) are among the most compelling candidates for particle dark matter. These particles can be gravitationally captured by massive celestial bodies, such as the Sun, where they accumulate and, according to theoretical models, eventually self-annihilate into Standard Model particles, including neutrinos. Neutrino telescopes - large arrays of photo-sensors...
Hadronic cross sections are one of the dominant sources of uncertainty for the measurement of Galactic Cosmic Ray (GCR) fluxes with calorimetric experiments. Refining these cross sections can serve as an important step towards obtaining a better understanding of GCR production and propagation. This work presents measurements of hadronic cross sections for protons and helium-4 using data from...
The LHAASO~J2018+3651 region is one of the brightest sources in the sky at TeV energies. Photons with energies up to ∼0.27 PeV from this region have been detected with the Large High Altitude Air Shower Observatory (LHAASO) and here we present a detailed study of this region using more data from LHAASO. This analysis resolves the region into six sources: LHAASO~J2018+3641, LHAASO~J2019+3649,...
We present an updated catalog of TeV gamma-ray sources using data from the 5th reconstruction pass of data from the High Altitude Water Cherenkov Observatory (HAWC). In addition to improved reconstruction and nearly three years of additional data, this new catalog uses a systematic multi-source fitting procedure to model the data with much greater flexibility and accuracy. Besides including a...
PUEO (the Payload for Ultra-high Energy Observations) is an Antarctic, balloon-borne experiment that aims to detect neutrinos above EeV energies primarily by searching for Askaryan radiation sourced from particle cascades induced by interactions within the ice. At the highest energies, neutrinos predominantly undergo charged-current interactions, producing high energy charged leptons which can...
The RadMap Telescope is a compact instrument designed to characterize the primary spectrum of cosmic-ray nuclei and the secondary radiation field created by their interaction with the shielding of spacecraft. Its main purpose is to precisely monitor the radiation exposure of astronauts, and it is the first instrument with a compact form factor that can measure both the charge and energy of...
The current Fermi-LAT source catalog (4FGL-DR4: 7194 sources over 14 years) was built incrementally from the 8-year catalog by adding newly discovered sources but keeping the positions of existing sources fixed. Now, after 16 years (reached in August 2024) there are twice as many data as used in the original 4FGL catalog, enabling much more precise source positions. It is thus time to...
The High Energy Stereoscopic System (H.E.S.S.) collaboration reported the emission of two extended sources, HESS J1857+027 and HESS J1858+020, with no known counterparts with an approximate separation of 1 degree. However, in the 3HWC catalog, the High-Altitude Water Cherenkov (HAWC) collaboration reported the emission of 3HWC J1857+027. We present a multi-source fitting analysis of the HESS...
Radio detection is the most promising experimental strategy to study the extremely low flux of EeV-scale neutrinos from the cosmos. Neutrinos interacting in the polar ice sheets produce electromagnetic radiation through the Askaryan mechanism, which is detectable at long distances by radio antenna arrays embedded in the ice. While Askaryan radio emission from neutrinos has yet to be observed,...
Cosmic rays are an abundant, and not complete known, natural source of ionizing and photonizing radiation from outer space, where multiple techniques have been invented to detect and study them. In order to detect and study them, we planned, designed and simulated a detection system consisting of two identical detectors based on cylindrical transparent acrylic rods of $20\, cm$ high and...
Over the past 16 years, the Fermi Large Area Telescope (LAT) has significantly advanced our view of the GeV gamma-ray sky, yet several key questions remain - such as the nature of the isotropic diffuse background, the properties of the Galactic pulsar population, and the origin of the GeV excess towards the Galactic Centre. Addressing these challenges requires sophisticated astrophysical...
Atmospheric neutrinos play a dual role in particle physics: they are crucial signals for studying neutrino oscillations and serve as significant backgrounds in searches for the diffuse supernova neutrino background, proton decay, dark matter, and other rare processes. To address unresolved questions in neutrino oscillation physics and to identify rare events, precise predictions of atmospheric...
IceCube-Gen2 is a proposed neutrino observatory at the South Pole that will build on the success of IceCube and will also serve as a unique detector for cosmic-ray air showers.
Analogous to the IceTop surface array over IceCube’s deep optical detector, IceCube-Gen2 will also feature a surface array above an optical array deep in the ice. As improvement over IceTop, the IceCube-Gen2 surface...
Weakly Interacting Massive Particles (WIMP) are interesting dark matter (DM) candidates because they exhibit the usual DM properties (such as being non-relativistic and electrically neutral), while having the advantage of weakly interacting with Standard Model particles, which makes them detectable in principle. When DM decays or annihilates, neutrinos are produced. Therefore, an indirect...
The radio-frequency emissions produced by particle showers on Earth, resulting from cosmic rays (CRs) and neutrinos originating from highly energetic sources, share significant similarities, enabling radio detectors initially designed for ultra-high energy neutrino (UHE-$\nu$) searches to also study CRs. The Askaryan Radio Array (ARA), an experiment currently operating within the ice at the...
Before the start of CERN in 1954, cosmic rays (CR) were the main source of high energy particles leading to the discovery of anti-matter, muons and first mesons. Then particle accelerators provided controlled environments for studying high-energy particle interactions, producing precise data leading to the development of the Standard Model. These data were used early-on to create models to...
Quasi-periodic eruptions (QPEs) are high-amplitude, soft X-ray flares that repeat on timescales of hours-days, and have been discovered recently in the nuclei of some galaxies. These remarkable and mysterious repeating transients are thought to be associated with the supermassive black holes in these galaxies. QPEs have could provide powerful new constraints on accretion physics (if caused by...
In this talk, we present our study of the cosmic antiproton and antideuteron fluxes produced by the evaporation of galactic primordial black holes (PBHs). The antimatter production spectra were obtained using our modified version of the BlackHawk code, which incorporates a state‐of‐the‐art Wigner function coalescence model for antideuteron formation. The propagation of these fluxes throughout...
The TA Low-energy Extension (TALE) experiment extends the reach of the TA experiment on the low-energy side to below $10^{16}$ eV. A primary objective of TALE is to study the transition from galactic to extragalactic cosmic rays. The TALE detector is a hybrid observatory composed of fluorescence telescopes and a surface detector array of scintillation counters. The surface detectors are...
Imaging with Cherenkov telescopes was a breakthrough for gamma ray astronomy. However, by pushing Cherenkov telescopes to ever higher precision and ever larger sizes our upcoming generation of telescopes has reached the intrinsic limits of imaging itself. Aberrations limit our field-of-view and the angular resolution in the gamma-ray sky. The square-cube-law escalates the costs to construct...
Microquasars have been shown to be capable to accelerate particles to energies well above 100~TeV. The reported presence of hadronic particles in their jets makes them one of the most convincing PeVatron candidates. Their proximity to Earth allows detailed studies of their morphology, providing unique laboratories for the study of particle acceleration in jets. The LHAASO Observatory has...
The diffuse astrophysical neutrino flux measured in the very high energy range introduced unresolved issues about the origin of these events and underlined as a viable solution the multi-component scenario. Recent studies show that galaxies with high star formation rate (above teens Mo/year) can be responsible of a seizable fraction of the observed astrophysical flux. Despite their low...
Primordial Black Holes~(PBHs) are hypothetical black holes with a wide range of masses that formed in the early universe. As a result, they may play an important cosmological role and provide a unique probe of the early universe.
A PBH with an initial mass of approximately $10^{15}$~g is expected to explode today in a final burst of Hawking radiation. In this work, we conduct an all-sky...
We have shown in [1] that at ultra-high-energy (UHE) the Galactic diffuse gamma-ray emission is very patchy, due to the short residence time of cosmic rays in the Galaxy and the scarcity of Galactic PeVatrons. However, such a patchiness remains hard to firmly attribute to the diffuse component of the Galactic emission due to the presence of a population of unresolved pulsars whose contribution...
Ground based gamma ray measurements with IACTs suffer from irreducible backgrounds from a specific type of cosmic-ray induced air showers. These air showers are characterized by a large electromagnetic component which is mostly due to highly energetic neutral pions produced in the primary interaction of cosmic rays with atmospheric nuclei. Current event generators that model these hadronic...
The Askaryan Radio Array (ARA) is a five-station, in-ice radio detector located at the South Pole searching for particle cascades from cosmogenic and astrophysical neutrinos with >1e17 eV of energy. Cascades in this energy regime emit radio-wavelength Askaryan radiation that can be observed by one or more ARA stations. With the recent Km3Net observation of an approximately 2e17 eV neutrino,...
The detection of very high-energy (VHE) and ultra-high-energy (UHE) emissions associated with micro-quasars has unveiled a new class of powerful particle accelerators. The particles are suggested to be accelerated within their jets or surrounding environments. Cygnus X-1 and Cygnus X-3 are two prominent micro-quasars located in the Cygnus region. Significant efforts have been dedicated to...
The Telescope Array (TA) experiment has been observing extensive air showers (EAS) induced by ultrahigh energy cosmic rays (UHECR) since 2008. The TAx4 upgrade aims to expand the detection area of TA at the highest energies to four times its original size with 500 additional surface detectors (SD) with the nearest neighbor spacing extended from 1.2km to 2.08km. Half of the new detectors were...
Very high-energy gamma-ray emission from the microquasar V4641 Sgr with energy up to beyond 100 TeV has been recently detected with the H.E.S.S., HAWC, and LHASSO observatories. The gamma-ray emission reveals a puzzling 200-parsec-long structure significantly misaligned with its radio jet. We propose that this gamma-ray structure is produced by high-energy cosmic-ray particles escaping from...
The centre of the Milky Way hosts the most massive and dense clouds of molecular hydrogen gas in our Galaxy. The inferred star formation efficiency at the Galactic Centre is however surprisingly low given the large gas reservoir. Yet the huge uncertainty in the measurement makes the comparison between observations and theories difficult. Measurements of the gas density based on different mass...
FASER (the Forward Search Experiment) is a compact detector located about 480 m downstream of the ATLAS interaction point at CERN’s Large Hadron Collider (LHC). It is designed to explore new Beyond the Standard Model (BSM) physics by searching for light, weakly interacting, and long-lived particles (LLPs) produced in the far-forward region. This unique setup—shielded by approximately 100 m of...
The IceCube Neutrino Observatory, located at the South Pole, covers a cubic kilometer of Antarctic ice, designed to detect astrophysical neutrinos in the TeV-PeV energy range. While IceCube has recently identified a diffuse flux of neutrinos originating from the Galactic Plane, specific sources of astrophysical neutrinos within the Milky Way remain elusive. Hadronic gamma-rays, produced...
The current generation of Imaging Atmospheric Cherenkov Telescopes (IACTs: HESS, VERITAS and MAGIC) has led to a renaissance in the use of stellar intensity interferometry for sub-milliarcsecond optical astronomy. This technique, used over distances of O(100 m) between telescopes, enabled the measurement of stellar radii on the order of a few hundred micro-arcseconds with a ~10% resolution...
A fundamental challenge for observations with Imaging Atmospheric Cherenkov Telescopes is the treatment of the dominant background of cosmic-ray initiated air showers. Traditional frequentist methods for signal estimation rely on gamma-hadron separation cuts to remove a large fraction of background events (reducing the efficiency of gamma-ray detection). In this work we adopt and extend a...
Recently, LHAASO published its measurement of the Galactic diffuse gamma-ray emission in the $\rm{TeV}-\rm{PeV}$ range, which seemed to be $2$ to $3$ times higher than theoretical expectations. To explain the apparent discrepancy, an important contribution from a population of unresolved pulsars or important spatial variations in the cosmic-ray density have been proposed. We show through a...
The death of massive stars is accompanied by the formation of central and accreting compact objects and the subsequent launch of relativistic jets. However, not all jets successfully drill their way out of the stellar envelope, which would result in gamma-ray emission. Unsuccessful jets, also known as choked jets, might still produce radiation at lower frequencies by dissipating the jet energy...
SQM-ISS is a detector that will look for massive particles among cosmic rays from the International Space Station. Some of these candidates include strange quark matter, Q-balls, lumps of fermionic exotic compact stars, primordial black holes, mirror matter, Fermi balls and others. These compact and dense objects are expected to be much heavier than normal nuclei, to travel at speeds typical...
The Radio Neutrino Observatory in Greenland (RNO-G) is located at Summit Station and is designed to detect Askaryan emission from ultra-high energy (UHE) neutrinos above 100 PeV. The detector is proposed to have 35 stations of which 8 have been built so far. Each station is made up of antennas that are buried at a depth of 100 meters with the purpose of triggering on and reconstructing...
Imaging atmospheric Cherenkov telescopes (IACTs) detect extended air showers (EASs) generated when very-high-energy (VHE) gamma rays or cosmic rays interact with the Earth's atmosphere. Cherenkov photons produced during an EAS are captured by fast-imaging cameras, which record both the spatial and temporal development of the shower, along with calorimetric data. By analyzing these recordings,...
Binary neutron star (BNS) mergers are the source of most ultrahigh-energy cosmic rays, making them key astrophysical events for multi-messenger studies. The joint detection of gravitational waves (GW170817 by GW detectors) along with spatially coincident short gamma-ray burst (sGRB) GRB170817A has established a clear connection between BNS mergers and sGRBs. In our recent study, we investigate...
In this contribution, a search for neutrino emission from the Central
Molecular Zone (CMZ) and the Cygnus Cocoon is presented exploiting
KM3NeT/ARCA capabilities. The CMZ extends for a few hundred par-
secs around the Galactic center, containing the massive molecular clouds
Sgr A, Sgr B, and Sgr C. The Cygnus Cocoon is a massive star-forming
region of a few hundred parsecs in the...
Cygnus X-3 is a microquasar consisting of a compact object of unknown nature and a Wolf-Rayet star, which orbit each other with a very short period of 4.8 hours. The compact object launches powerful jets that are an excellent site for particle acceleration up to relativistic energies. The presence of these relativistic particles, combined with the proximity to the star and its high luminosity,...
Magnetic monopoles are beyond standard model particles, predicted by Grand Unified Theories (GUTs) to be created during the early universe. At typical masses of the GUT-scale - above $10^{14}$ GeV - these particles would move at sub-relativistic speeds. The Rubakov-Callan effect predicts that magnetic monopoles can catalyze nucleon decays, in particular the decay of protons. This results in a...
Abstract: The VERITAS Stellar Intensity Interferometer (VSII) uses an intensity interferometric technique to measure the angular extent of stellar envelopes of hot (OBA) stars and binary systems. VSII has previously demonstrated the ability to reconstruct the sub-milliarcsecond angular diameters of individual stellar photospheres (eps Ori, bet CMa, bet Uma) with a precision better than 5%....
LS 5039 is a High Mass X-ray Binary (HMXRB) comprising a compact object in an eccentric 3.9 day orbit around a massive O6.5V star. It is one of the most studied object in the field. A first HESS publication in 2004 established multi-TeV emission from the system (first ever TeV binary system). A second publication in 2006 , based on a deeper data set of ∼ 70h of observation, established the TeV...
The IceTop array at the surface of the IceCube Neutrino Observatory measures extensive air showers produced by cosmic-ray particles with energies from PeV up to EeV, covering the transition region from galactic to extragalactic sources. This contribution presents significant improvements that will enhance the measurement of the IceTop energy spectrum. (I) To analyze more than a decade of data...
TAROGE-M comprises autonomous radio antenna arrays operating at 180--450 MHz frequencies on top of ~2.7 km-high Mt. Melbourne in Antarctica, designed to detect near-horizontal ultra-high-energy (UHE) air showers with energies >0.3 EeV. The primary goal is to detect more of the so-called ANITA anomalous events — air-shower-like events from below the horizon, which cannot be explained by tau...
Along with their gamma-ray observations at very high energies (VHE, 20 GeV - 100 TeV), the two 17-m MAGIC telescopes (at Roque de los Muchachos Observatory, La Palma, Spain) have also been utilized as an optical stellar intensity interferometer (SII) for the last six years. The calibration and validation of the setup, alongside the first measurement of the stellar angular diameter of 13...
The binary LS I +61$^{\circ}$ 303 was discovered as a gamma ray emitter nearly fifty years ago and has since been the subject of extensive observations across the electromagnetic spectrum. Composed of a primary Be star and a neutron star, LS I +61$^{\circ}$ 303 exhibits complex periodic behavior and variability from radio wavelengths to very-high-energy gamma rays (VHE, E>100 GeV), with...
An international collaboration composed of Italian, Japanese, Spanish and Swiss institutes, is developing the advanced camera (AdvCam), the next-generation camera for Imaging Atmospheric Cherenkov Telescopes, designed specifically for the Large-Sized Telescopes (LST) of the Cherenkov Telescope Array Observatory. AdvCam incorporates cutting-edge Silicon Photomultipliers (SiPMs) and a fully...
The NICHE array at Telescope Array is a non-imaging Cherenkov light detector situated close to the Telescope Array Middle Drum fluorescence detector site. It has been operating since September 2017. Data collected between June 2020 and July 2024 has been analyzed and we will present the energy spectrum of the cosmic rays observed. The threshold energy of the detector is about 1 PeV and the...
The IceCube Neutrino Observatory, a cubic-kilometre detector embedded in the glacial ice of the South Pole, is designed to detect neutrinos across a broad energy range, from a few GeV to several PeV. This enables precise measurements of the neutrino energy spectrum, comprising the diffuse astrophysical flux, the conventional atmospheric flux from pion and kaon decays, and the not yet detected...
The MAGIC telescopes are two imaging atmospheric Cherenkov telescopes (IACTs) located at the Roque de los Muchachos Observatory (La Palma, Spain). Many observations performed with a high night-sky background have been dedicated to stellar intensity interferometry (SII), since very-high-energy (VHE, 20 GeV - 100 TeV) gamma-ray observations have reduced sensitivity during these periods. The...
In rare events experiments, such as those devoted to the direct search of dark matter, a precise knowledge of the environmental gamma and neutron backgrounds is crucial for the design of appropriate shieldings. The neutron component is often poorly known due to the lack of a scalable detector technology for the measurement of low-flux neutron spectra in a short time.
Thanks to their high...
HAWC and LHASSO reported very high energy (VHE) gamma rays with energies exceeding 100 TeV from five Galactic black hole binaries. The spatial extent of the VHE gamma rays is several tens of pc, which is much larger than the size of a black hole binary system. Some black hole binaries have different gamma-ray spectra, some of which are steeper than predicted by the standard shock acceleration...
The AdvCam is a next-generation camera for the Large-Sized Telescopes of the Cherenkov Telescope Array Observatory, based on silicon photomultipliers. Its fully digital readout system enables the design of new, sophisticated trigger logic.
The Large-Sized Telescopes aim to cover the low-energy range of the cosmic gamma-ray spectrum, with a threshold starting at about 20 GeV, using the...
KM3NeT/ORCA is a water-Cherenkov neutrino telescope currently under construction in the Mediterranean Sea, aimed at measuring atmospheric neutrino oscillations and determining the neutrino mass ordering. The detector consists of a three-dimensional array of detection units, each equipped with 18 digital optical modules, which house 31 photomultiplier tubes. The Cherenkov light induced by...
A resolved optical image of a gamma-ray emitter would be of enormous scientific interest. For gamma-ray sources associated with interacting stars (colliding winds or novae), stellar intensity interferometry (SII), envisioned as a second observing mode at the Cherenkov Telescope Array Observatory (CTAO), could yield images of the systems in visible light. Recent radius measurements of massive...
The RES-NOVA project detects cosmic neutrinos (i.e., Supernovae) via coherent elastic neutrino-nucleus scattering (CEνNS) using archaeological Pb-based cryogenic detectors. The high CEνNS cross-section, due to the Pb's large atomic mass, and ultra-high radiopurity of archaeological Pb enable a highly sensitive, cm-scale observatory equally sensitive to all neutrino flavors. These features are...
We have built a prototype of stereoscopic water Cherenkov detector array (SWCDA) inside the Tibet ASgamma air-shower array (Tibet-III array) by the end of 2024. The SWCDA project is the next generation of innovative ground-based stereoscopic water Cherenkov detection array, its main scientific goal is to observe 100GeV-10TeV high-energy gamma-ray astronomy, such as observation of blazars,...
The Large High Altitude Air Shower Observatory (LHAASO) provides unprecedented capabilities for measuring cosmic-ray (CR) properties in the high energy regime. The LHAASO experiment has achieved unprecedented precision in measuring the cosmic ray all-particle energy spectrum and its mean logarithmic mass in the "knee" region. As statistics accumulate, it becomes feasible to accurately assess...
The identification of cosmic objects emitting high energy neutrinos provides new insights about the Universe and its active sources. The existence of cosmic neutrinos has been proven by the IceCube Neutrino Observatory, however the big question of where these neutrinos originate from remains largely unanswered. The KM3NeT detector for Astroparticle Research with Cosmics in the Abyss (ARCA) is...
The quantum properties of a gas of bosons were predicted by Einstein 100 years ago. The first experimental measurements of its consequences were performed by Hanbury-Brown & Twiss in 1954, when measuring the size of bright stars by correlating the arrival times of photons detected by two optical telescopes. Extremely large telescopes, 10ps resolution single photon detectors bring the key...
In the context of astroparticle physics, nuclear astrophysics, and quantum computing projects, identifying underground laboratories where cosmogenic background is suppressed is crucial.
Located approximately 500 meters from the center of Trento, Italy, the Piedicastello tunnels are covered by 100 meters of limestone rock from the Doss Trento hill. The site spans over 6,000 square meters and...
The GRAPES-3 experiment, located in Ooty, India (11.0^{o}N, 76.7^{o}E, 2200 m a.s.l.), uses a dense array of 400 plastic scintillator detectors and a 560 m^{2} tracking muon detector to measure all charged particles and the muonic components of cosmic ray showers, respectively. The experiment has measured the cosmic ray proton spectrum in the energy range of 50 TeV to 1.3 PeV, and the relative...
Since the recent detection of very-high-energy (VHE; $E>0.1$ TeV) gamma rays, microquasars have gained more and more attention as potential PeVatron candidates. Among them, the microquasar SS 433 and its nebula W50 stand out as the first to be detected in VHE gamma rays. HAWC and H.E.S.S. reported TeV gamma-ray emission from knot-like structures in the outer lobes, likely powered by jets...
The IceCube Neutrino Observatory has provided new insights into the high-energy universe, in particular, unveiling neutrinos from the galactic plane. However, galactic neutrino sources are still unresolved. The recent detection of multi-PeV photons by LHAASO from the Cygnus region highlights its potential as a galactic neutrino source. Additionally, LHAASO, HAWC, and HESS have reported over...
Iron cosmic rays represent the most abundant heavy nuclei at energies above 1 TeV, with their production thought to be primarily originated by astrophysical sources. Therefore, measuring the iron spectrum provides crucial insights into the origin, acceleration, and propagation mechanisms of cosmic rays. Recent results from space-based detectors have revealed unexpected energy dependences in...
By analyzing the radio emissions from air showers using interferometry, we can estimate their properties. In this contribution, we apply interferometry to reconstruct air-shower parameters based on measurements taken with the Auger Engineering Radio Array (AERA) at the Pierre Auger Observatory. This reconstruction method is achievable at AERA through precise clock synchronization with a beacon...
Recent measurements of astrophysical neutrinos have expanded our understanding of their nature and origin. However, very little is still known about the astrophysical $\nu/\bar{\nu}$ ratio. The only prior measurement is the recent, single Glashow event seen by IceCube. Understanding the astrophysical $\nu/\bar{\nu}$ ratio has a bearing on multiple questions, including the astrophysical...
The first Large-Sized Telescope (LST-1) of the Cherenkov Telescope Array (CTA), located on La Palma, has been operational since 2018 and remains in its commissioning phase. Over the past years, LST-1 has delivered a number of significant scientific results, including the detection of active galactic nuclei flares, observations of pulsar wind nebulae and pulsars, the detection of a nova, and...
The Cherenkov Telescope Array Observatory (CTAO) is often described as the world's most powerful ground-based gamma-ray observatory. This is particularly true in the time domain.
The collection areas of Fermi-LAT, LHAASO, and the CTAO are approximately 1, 10³, and 10⁵ m², respectively, above a threshold of 50 GeV. In a signal-dominated regime, the event rate above 50 GeV is expected to be...
TRopIcal DEep-sea Neutrino Telescope (TRIDENT) features the hybrid digital optical module (hDOM) as the detector unit, containing large-area silicon photomultiplier (SiPM) arrays combined with photomultiplier tubes to boost photon detection efficiency and timing capability, which is crucial to angular resolution performance of TRIDENT. We are developing a 16-channel fast-timing...
The identification of potential sources of ultra-high-energy cosmic rays (UHECRs) remains challenging due to magnetic deflections and propagation losses, which are particularly strong for nuclei. In previous iterations of this work, we proposed an approach for UHECR astronomy based on Bayesian inference through explicit modelling of propagation and magnetic deflection effects. In this...
A precise understanding of the optical properties of the instrumented Antarctic ice sheet is crucial to the performance of optical Cherenkov telescopes such as the IceCube Neutrino Observatory and its planned successor, IceCube-Gen2.
One complication arising from the large envisioned footprint of IceCube-Gen2 is the larger impact of the so-called ice tilt. It describes the undulation of ice...
We present here a data exploration tool designed to enhance the study of astrophysical objects by integrating traditional hierarchical clustering with graph-based community detection algorithms. This new tool allows in-depth analysis of the distributions of observables across astrophysical catalogs, while overcoming common challenges arising from the use of clustering algorithms that are not...
Active Galactic Nuclei (AGN) and their relativistic jets that emit radiation covering almost the entire electromagnetic spectrum have been few of the most fascinating subjects in astronomy for decades, yet the composition of these relativistic jets is still not clearly known. The origin of the high energy peak in the Spectral Energy Distribution (SED) of blazars has been an open question in...
In recent years, the development of orbital and sub-orbital missions aiming to the use the Earth’s atmosphere as the target mass to detect extensive air showers (EAS) induced by ultra-high energy (UHE) CRs and neutrinos through their EM counterparts – such as EUSO-SPB2, the Terzina Payload onboard the NUSES missions, and the planned POEMMA mission – has driven interest in modeling the expected...
The interaction cross section of charged pions with air nuclei is a critical parameter for accurately simulating extensive air showers. Improving the modeling of high-energy pion interactions is essential for addressing the muon puzzle—the observed deficit of muons in simulations compared to indirect experimental estimates. As collider experiments cannot directly probe these interactions, we...
The long-term operation of HAWC provides valuable opportunities to study transient and variability phenomena in sources emitting at TeV energies. In this work, we introduce the All-sky Root around in an Unbiased way (ARU) algorithm, a tool designed to estimate the significance of deviations from constant emission on different timescales using data from ground-based gamma-ray observatories. We...
The detection of extensive air showers using radio antennas has evolved into a mature technique, complementing particle detector arrays by providing sensitivity to the longitudinal development of the showers and enabling an independent determination of the cosmic-ray energy. Both the Pierre Auger Observatory in Argentina and the IceCube Neutrino Observatory at the South Pole have been...
The AMS-02 spaceborne particle spectrometer has measured the cosmic-ray flux of positrons with high precision, reaching up to hundreds of GeV. This has provided invaluable insights into the local sources of antimatter in cosmic rays. The hypothesis that pulsars and their nebulae are responsible for the cosmic ray positron flux has recently gained further support from observations of gamma-ray...
We have built a 100 m2 prototype stereoscopic water Cherenkov detector array (SWCDA) in the Tibet air-shower array in 2024, which will be used for gamma-ray astronomy observations in the 100 GeV-10 TeV energy range. In this paper, we describe the design of the Tibet stereoscopic water Cherenkov detector and detailed Monte Carlo simulations to demonstrate the performance and sensitivity of...
The Cherenkov Telescope Array Observatory is a state-of-art ground-based gamma-ray observatory that is currently in construction phase. The four Large-Sized Telescopes form the core of the Northern observatory, each with a dish diameter of 23 m, designed to cover the low-energy range with a threshold starting at 20 GeV. The first Large-Sized Telescope (LST-1), is already operating and...
Cosmic Ray Neutron Sensing (CRNS) is a technique to measure water content in soil or snow on the hectare scale through the measurement of epithermal neutrons above the ground.
The measurement of epithermal neutrons needs to be corrected for the change in solar modulation affecting the incoming cosmic ray flux.
In addition, the specific geomagnetic conditions of the measurement location have...
Cherenkov telescopes (IACTs) require synchronization at the nanosecond scale for real-time event tagging and common triggering, enabling coincidence detection across multiple telescopes. Even more stringent timing is required for intensity interferometry, where the light intensity fluctuations of a source are sampled at multiple telescopes and correlated to reveal a source size-dependent...
The Latin American Giant Observatory (LAGO) is an observatory focused on the detection of cosmic rays and space weather phenomena using a network of water Cherenkov detectors. Currently, LAGO is transitioning to new hardware with higher time resolution, which requires an improvement and adaptation of the current calibration algorithms. In this work we present an improvement of such algorithm...
The Askaryan Radio Array (ARA) has been operating at the South Pole for over a decade, searching for ultra-high-energy astrophysical and cosmogenic neutrinos using the Askaryan effect. ARA has always been at the forefront of testing innovative trigger designs and advancing electronic upgrades, with ongoing DAQ improvements over the past 2–3 years and a long-term plan to transition to Radio...
Ground based observations of cosmic rays provide one of the most effective methods for investigating the effects of solar activity in near-Earth space. The Akeno muon telescope, which has a similar detection technique configuration and energy threshold for incoming atmospheric muons as the GRAPES-3 muon telescope, serves as one such observation system. The Akeno muon telescope's field of view...
The performance of a neutrino telescope is fundamentally dependent on the optical properties of its detection medium. For deep-sea neutrino telescopes like TRIDENT, an accurate real-time, in-situ optical calibration system is essential due to the dynamic nature of the deep-sea environment. A camera-based optical calibration system was initially demonstrated in the TRIDENT Pathfinder experiment...
Multimessenger astronomy seeks to uncover the origins of cosmic rays and neutrinos. The IceCube Neutrino Observatory plays a key role in monitoring the sky for revealing high energy neutrinos and neutrino time clusters possibly associated with astrophysical sources, issuing alerts to the astrophysical community for significant excesses. This enables joint observations with other astronomical...
Neutron monitors are essential instruments for studying interplanetary conditions and space weather. Complementing to space-born detectors, they extend the observable energy range beyond 50 GeV. While ground-level enhancements and Forbush decreases are well-documented, shorter temporal increases in neutron count rates remain under-explored. This work investigates potential causes of such short...
Since 2019 a set of three scintillator-based small muon telescopes of the Extreme Energy Events (EEE) Project have been successfully installed and operated at the high latitude (79° N) site of Ny-Ȧlesund, in the Svalbard archipelago. Such detectors have been employed for various analysis, also including the observation of Forbush decrease events in regions characterized by a low geomagnetic...
IC 443 is a well-known supernova remnant that stands out due to its interaction with a dense molecular cloud, creating a complex environment where shocks can efficiently accelerate particles to high energies. This makes it a key target for investigating the mechanisms of cosmic-ray acceleration and gamma-ray production, particularly in the context of supernova remnants as potential sources of...
The study of galactic cosmic ray (GCR) variations and their connection to solar activity has been explored using various methods, such as cross-correlation analysis, which measures the synchronization between time series peaks, and power spectral density or wavelet analysis. Here, we investigate the potential of advanced signal processing techniques, specifically Empirical Mode Decomposition...
Astrophysical collisionless shocks are efficient particle accelerators, for which some pre-acceleration mechanism is needed in order for electrons to participate in diffusive shock acceleration. In this work, we investigate how pre-existing turbulence may be able to modify the shock structure, plasma instabilities, and ultimately particle acceleration. We perform linear analysis of wave modes...
Analysis of anisotropy of the arrival directions of galactic positrons, electrons and protons has been performed with the Alpha Magnetic Spectrometer on the International Space Station. This measurement allows to differentiate between point-like and diffuse sources of cosmic rays for the understanding of the origin of high energy positrons or the hardening in the proton flux. The AMS results...
The IceCube Collaboration has recently reported compelling evidence of high energy neutrino emission from NGC 1068, and mild excesses for other 3 local Seyfert galaxies. This sparked a surge of interest in neutrino emissions from the hot coronae around supermassive black holes in Seyfert galaxies. In this talk, I demonstrate that these sources are consistent with sub-equipartition between...
The arrival time distributions of air shower particles provide critical insights into the development of extensive air showers and the properties of primary cosmic rays. This study analyses the temporal characteristics of secondary particles detected by the KM2A detectors of the Large High Altitude Air Shower Observatory (LHAASO). We propose a novel parameterized function to describe the...
In the era of real-time astronomy, citizen scientists play an increasingly important role in the discovery and follow-up of transient astrophysical phenomena. From local astronomical societies to global initiatives, amateur astronomers contribute valuable observational data that complement professional efforts. Astro-COLIBRI facilitates these contributions by providing a user-friendly platform...
Tau neutrinos are among the least studied particles in the Standard Model due to the challenges in producing and detecting them. One of the primary sources of tau neutrinos is astrophysical events, where they are mainly produced through flavor oscillations. This flux has been detected by neutrino telescopes like IceCube, but identifying the tau component of the flux — especially at TeV-scale...
The Telescope Array Observatory (TA) located in Utah, U.S.A., is dedicated to the study of ultra-high-energy cosmic rays (UHECRs). The project's primary aim is to investigate the energy spectrum, origin, and composition of these cosmic rays. TA employs a hybrid detection method, using surface detectors (SDs) in combination with fluorescence detectors (FDs). The observation of air showers by...
At ultra-high energies, the flux of cosmic rays is too low for direct measurements to be meaningful. When a cosmic ray enters the atmosphere, it initiates an extensive air shower, producing a cascade of secondary particles that propagate toward the ground. Large arrays of surface detectors are used to measure these secondary particles upon arrival.
The signal detected at a specific...
The Pierre Auger Observatory (Auger) and the Telescope Array (TA) are the world’s two largest ultra-high-energy cosmic ray (UHECR) observatories. They operate in the Southern and Northern hemispheres, respectively, at similar latitudes but with distinct surface detector (SD) designs. A significant challenge in studying UHECR physics across the full sky is the apparent discrepancy in flux...
High-precision measurements of proton and helium nuclei obtained from direct cosmic ray experiments provide valuable insight into the mechanisms of CR acceleration and propagation in the Galaxy.
The space-based calorimeters, CALET as well as DAMPE, have recently revealed an additional spectral feature at tens of TeV, i.e. a softening of the flux, which is not predicted by traditional...
Gamma-ray measurements using the imaging atmospheric Cherenkov technique currently achieve the highest angular resolution in astronomy at very high energies, reaching down to arcminute scales at multi-TeV energies. High-resolution measurements provide the key to progress on many of the central questions in high-energy astrophysics, including the sites and mechanisms of particle acceleration up...
A complete understanding of compact binary coalescences requires combining gravitational wave (GW) observations with broadband electromagnetic data. The detection of GeV-TeV gamma rays will be crucial for probing the acceleration processes and environments near compact object mergers. The binary neutron star (BNS) merger GW170817 provided the first direct evidence that BNS mergers are...
GRANDProto300 is one of the prototype arrays of GRAND (Giant Radio Array for Neutrino Detection) in China, covering an area of 200 ${\rm km}^2$ with radio antennas. The construction of the array will be completed in 2026 and it aims to demonstrate the autonomous detection of radio emission from air showers produced by high-energy astroparticles. We calculate the exposure of GRANDProto300 using...
Recent experimental results on the arrival direction of high-energy cosmic rays have motivated studies that call for a deeper understanding of their propagating environment. Interstellar and local magnetic fields shape this observed anisotropy. In coherent magnetic structures, such as the heliosphere, or due to magnetohydrodynamic turbulence, magnetic mirroring can temporarily trap particles,...
The Calorimetric Electron Telescope (CALET) on board the International Space Station (ISS) is a space-based instrument consisting of a CHarge Detector (CHD) made of plastic scintillators, a thin (3 radiation lengths, X0) tungsten-scintillating fibre IMaging Calorimeter (IMC) for accurate particle tracking and identification, and a thick (27 X0, 1.3 nuclear interaction length) Total AbSorption...
The study of astrophysical sources with extended very-high-energy (VHE) emission is crucial for advancing our understanding of the most energetic processes in the Universe. Observatories such as HAWC and LHAASO have been pioneers in this field. The arrival of SWGO, with its wide field of view in the Southern Hemisphere, promises to open new frontiers in the study of extended sources, such as...
Detailed knowledge of the radiation environment in space is an indispensable prerequisite for space missions in low Earth orbit and beyond. The RadMap Telescope is a compact radiation monitor that can characterize the radiation environment aboard spacecraft and determine the biologically relevant dose received by astronauts. Its main sensor is a tracking calorimeter made from 1024...
Lorentz invariance (LI) is a fundamental symmetry in the Standard Model that may be violated in quantum gravity. The "Standard-Model extension" (SME) framework incorporates this hypothetical Lorentz invariance violation (LIV) by introducing a complete set of LI- and CPT-violating operators coupled with corresponding SME coefficients. A non-zero value of one or more of these coefficients would...
A primary advantage of Imaging Atmospheric Cherenkov Telescope (IACT) arrays over other ground-based gamma-ray detectors is their superior angular resolution. This capability is crucial for studying the morphology of gamma ray sources. Recent observations by ground-based detectors like LHAASO and HAWC have revealed a large number of extended TeV gamma-ray sources, highlighting the need for...
The Dark Matter Particle Explorer (DAMPE) is a space-based cosmic-ray observatory with the aim, among others, to study cosmic-ray electrons (CREs) up to 10 TeV. Due to the low CRE rate at multi-TeV energies, we increase the acceptance by selecting events outside of the fiducial volume. Non-fiducial events, with their complex topology, require special treatment with sophisticated analysis...
The extragalactic background is composed of the emission from all astrophysical sources, both resolved and unresolved, since the epoch of reionization, in addition to any diffuse components of exotic nature. In the last decade, there has been significant progress in our understanding of the cosmic history of extragalactic emissions associated with stellar evolution and accretion onto...
The Seyfert Type II galaxy NGC 1068 has been identified as a potential neutrino source by IceCube, with a 4.2σ significance detection of a 79+-22 neutrino excess from 2011 to 2020 (IceCube Collaboration 2020, 2024), despite the absence of a gamma-ray counterpart. The observed high-energy neutrino emission indicates the presence of a hadronic component, along with strong gamma-ray...
With the recent advancements in multi-messenger astrophysics, there is a clear need for a simulation framework that can self-consistently treat all cosmic messengers. To meet this demand, the latest developments in CRPropa provide versatile new tools for modelling the propagation of cosmic rays, gamma rays, electrons, and neutrinos across galactic and extragalactic environments, as well as in...
Back-coated mirrors offer an alternative to the standard front-coated mirrors, enhancing durability and long-term reflective properties by placing the exposed front coating behind a thin protective glass layer. This design ensures a long-term protection of the reflective layers, mitigating the effects of environmental exposure on the soft protective coating (typically quartz) and reflective...
Heliospheric modulation parameter (potential) ϕ based on a simple force-field approximation can be used to parametrize heliospheric modulation of galactic cosmic rays (GCRs) with a single term, which describes the average rigidity loss of a particle during heliospheric transport. Using this parameter with a LIS modulation model such as Vos & Potgieter (2015), we can estimate GCR fluxes that...
Dark photons (Dph) are cold dark matter candidates and bosons of a U(1)-like interaction to a hidden sector additional to the Standard Model (SM). For SM photons propagating in the Universe, a kinetic mixing with Dph can occur, allowing to perform indirect searches using the observed spectrum of galactic and extragalactic sources. To carry out the search, we use a model independent approach to...
The identification of gamma rays and suppression of cosmic-ray hadron background are crucial for very-high-energy gamma-ray observations and relevant scientific research of LHAASO-KM2A. Traditional machine learning methods, such as support vector machines, decision trees and deep neural networks have demonstrated promising performance in gamma-ray/hadron separation for ground-based experiments...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a planned water Cherenkov-based observatory to be located in Pampa La Bola, Chile, providing continuous, wide-field observations of the gamma-ray sky. SWGO will provide a unique view of the wide Southern Hemisphere gamma-ray sky, complementing other very-high-energy observatories such as HAWC, CTA and LHAASO. A key challenge in...
The Trasgos detector network is an initiative involving several research institutes and universities from Europe and Mexico, aimed at the detailed study of the cosmic ray background. Four MiniTrasgo detectors, each approximately 0.1 m² in size and equipped with tracking capabilities, have been built and installed across multiple countries. Currently, one of these detectors is being set up at...
The flat-field flasher is a calibration device designed for NectarCAM, the camera that will equip the Medium-Sized Telescopes (MSTs) of the northern site of the Cherenkov Telescope Array Observatory (CTAO). Positioned in the centre of MST dish, 16 meters in front of the camera, the flasher emits short (FWHM $<5$\,ns ), uniform (2-4%) light pulses to illuminate the entire focal...
Tracking detectors based on scintillating fibers, read out with silicon photomultipliers (SiPMs), have emerged as a competitive alternative to silicon strip detectors in high-energy and astroparticle physics. The scintillating-fiber tracker (FIT), proposed for the upcoming High-Energy Cosmic-Radiation Detection (HERD) facility, consists of several tracking planes of fiber mats stacked along...
The TRopIcal DEep-sea Neutrino Telescope (TRIDENT) is a next-generation neutrino observatory designed to detect high-energy astrophysical neutrino sources and significantly enhance the measurement of cosmic neutrino events of all flavors. At the chosen site in the South China Sea, TRIDENT Phase-I will deploy its first 10 strings, including approximately 200 hybrid digital optical modules...
The KM3NeT Collaboration is developing two deep-sea neutrino telescopes in the Mediterranean Sea. These telescopes use digital optical modules equipped with photomultipliers and acquisition electronics. Mounted on vertical strings, thousands of these modules are already in operation. Once completed, the telescopes will feature over six thousand synchronized modules, creating one of the world’s...
Binary systems are potential very-high-energy (VHE) gamma-ray emitters, however, the VHE gamma-ray emission mechanism of these systems remains poorly understood. Recent observational results from HAWC on V4641 Sgr and from H.E.S.S. on SS 433 suggest that shocks present on both sides of binary systems can efficiently accelerate particles. In this study, we search for VHE gamma-ray above ~10TeV...
Aiming to observe celestial gamma rays above 100 GeV, we have developed a new type of SWCDA (Stereoscopic Water Cherenkov Detector Array) for the EAS hybrid experiment. The first layer of each SWCDA unit is designed to observe the total energy and the direction of an air shower. The energy of primary cosmic rays can be inferred by measuring the total charge of secondary particles hitting the...
The Southern Wide-Field Gamma-ray Observatory (SWGO) is an international collaboration for the design and construction of the first wide-field gamma-ray observatory in the southern hemisphere. The observatory will be primarily based on surface water-Cherenkov detectors (WCD) sensitive to gamma rays from a few hundred GeV to the PeV. As part of the SWGO R&D activities, we developed a...
The ALPACA experiment is a composite air shower array experiment aiming to observe cosmic rays and gamma rays in TeV to PeV energy range in the Southern Hemisphere. The experiment consists of a 83,000 m2 surface detector array and 3,600 m2 underground water Cherenkov type muon detector in the Chacaltaya plateau (4,740 m a.s.l) in Bolivia. Currently, the prototype experiment is fully...
The ALPACA experiment is a new air-shower array experiment in Bolivia, with high sensitivity for gamma rays above 100 TeV. The prototype of the array, ALPAQUITA, is currently fully operational, with one about 1/4 of the total area of the full array.
With the goal of enabling long-term operation and future extensions, we have started developing new trigger electronics using modern...
The GRAMS (Gamma-Ray and AntiMatter Survey) program aims to deliver unprecedented sensitivities for astrophysical observations with MeV gamma rays and indirect dark matter searches with antimatter using a search for composite antinuclei (antideuteron and antihelium). GRAMS uses a Liquid Argon Time Projection Chamber (LArTPC) to detect cosmic-ray / gamma-ray events. The capability of the...
The Stereoscopic Water Cherenkov Detection Array (SWCDA) project is a next generation ground-based array experiment for high energy gamma-ray astronomy observation in the 100GeV-10TeV range. It is an innovative three-dimensional water Cherenkov detection array. Its main scientific objective is to observe blazars, active galactic nuclei (AGN or AGN flare), gamma-ray bursts, etc., in the 100...
The KM3NeT research infrastructure comprises two submarine Cherenkov neutrino telescopes at two corresponding abyssal sites in the Mediterranean Sea. KM3NeT/ARCA is the detector under construction off Portopalo di Capo Passero, Sicily, Italy, at a depth of 3500 m. While collecting data already in a partial configuration, KM3NeT/ARCA aims at a volume of 1 $\textnormal{km}^3$ instrumented with a...
Galaxies with AGN-Starburst composite nuclei, like e.g. NGC1068, are candidates for a number of high energy processes. In particular, using radio data to understand the magnetic field strength and structure in these cores aids us in understanding the transport of cosmic ray electrons and in gaining an insight into the non-thermal outflow of both the starburst and AGN regions.
Here we study...
The KM3NeT infrastructure comprises two water Cherenkov detectors in
the Mediterranean Sea. Each detector is composed of multiple optical modules
that are subject to movement due to deep-sea currents. To ensure an accurate
reconstruction of neutrino events, the position and orientation of each optical
module needs to be tracked continuously. This is performed by means of a dedicated...
GRAINE (Gamma-Ray Astro Imager with Nuclear Emulsion) is large-aperture-area observation project of cosmic gamma rays in the GeV/sub-GeV for precise by long balloon flights of the nuclear emulsion telescope. Nuclear emulsion is a charged particle detector with the highest spatial resolution based on the principle of silver halide photography. Due to the high spatial resolution (submicron) of...
In this study, we revisit the models of Fermi acceleration, incorporating Lorentz Invariance Violation (LIV) through a phenomenological approach. LIV is introduced via a modified Einstein's dispersion relation, along with an adjustment to the Lorentz factor. We calculate the energy spectrum and acceleration time of particles accelerated by first- and second-order Fermi mechanisms as a function...
Core Collapse Supernovae (CCSNe) are among the most energetic astrophysical events in the Universe. Despite huge efforts on understanding the main ingredients triggering such explosions, we still lack of compelling evidences for the precise mechanism driving those phenomena. CCSNe are expected to produce Gravitational Waves (GWs) due to asymmetric mass motions in the collapsing core, and emit...
The ALPACA experiment is currently under construction to achieve the first sub-PeV gamma-ray observations in the Southern Hemisphere. The observatory consists of a surface air shower array and underground muon detectors, following the successful design of the Tibet AS$\gamma$ experiment. As part of the initial phase, the ALPAQUITA array, comprising 97 surface detectors with 15$\,$m spacing,...
The Large Hadron Collider-forward (LHCf) experiment plays a fundamental role in the field of Ultra High Energy Cosmic Ray (UHECR) physics, since it provides calibration data for the tuning of the hadronic interaction models used in the simulations of Extensive Air Showers (EASs).
The LHCf experiment detects neutral particles produced in the very forward region of LHC collisions, thanks to its...
We investigate the potential contribution of radio galaxies (RGs) to ultra-high-energy cosmic rays (UHECRs) above $10^{18}$ eV. In earlier research, we used relativistic hydrodynamic simulations of jet-driven flows and a Monte Carlo method for cosmic-ray transport to show that shocks, turbulence, and relativistic shear can accelerate Galactic cosmic rays to energies exceeding $10^{20}$ eV. We...
In gamma-ray astronomy, detectors with high sensitivity in the MeV region, which have not yet been explored, are expected to be flown in space in the future [1]. In UVSOR synchrotron facility at Institute for Molecular Science, a MeV gamma-ray pulse source has been developed for user applications such as positron annihilation spectroscopy [2] and gamma-ray detector evaluation. Gamma rays with...
KM3NeT has recently reported the detection of a very high-energy neutrino event, while IceCube has previously set upper limits on the differential neutrino flux above 100 PeV but has yet to observe a neutrino event with an energy comparable to that of the KM3NeT detection. To improve diffuse measurements above 10 PeV, we apply machine learning techniques to enhance atmospheric muon background...
ServiMon is a scalable data collection and auditing pipeline designed for service-oriented, cost-efficient quality control in distributed environments, including the CTAO monitoring, logging, and alarm subsystems. Developed within a Docker-based architecture, it leverages cloud-native technologies and distributed computing principles to enhance system observability and reliability.
At its...
Searches for astrophysical neutrino sources in IceCube rely on an unbinned likelihood that consists of an energy and spatial component. Accurate modeling of the detector, ice, and spatial distributions leads to improved directional and energy reconstructions that result in increased sensitivity. In this work, we utilize our best knowledge of the detector ice properties and detector...
Charged cosmic-ray particles interact with the cosmic microwave background during their propagation over extragalactic distances. In the interaction known as the Greisen-Zatsepin-Kuzmin (GZK) effect, so-called GZK photons are generated via photo-pion production at ultra-high energy. The flux of GZK photons at Earth depends on different parameters of the cosmic-ray spectrum such as the spectral...
This work employs multivariate machine learning (ML) approaches to perform event reconstruction and gamma/hadron separation with the Tibet ASgamma experiment. We have simulated the entire composite array of the Tibet ASgamma experiment (Tibet III+MD), by using full Monte Carlo simulation. The simulation sample has been divided into two data sets, the high-energy data set (E > ~10 TeV) and the...
The surface detector of the Pierre Auger Observatory has recently been
upgraded with the addition of radio antennas, forming the Radio Detector (RD).
This
contribution outlines the standard methods for reconstructing extensive air
showers using the RD, along with recent developments.
The reconstruction pipeline is based on a robust understanding of the detector
itself. The entire...
Since 2021, the Open Data Portal has provided access to the Pierre Auger Observatory's data for both the scientific community and the general public. The data release process has been in place since the Observatory's foundation and continues to be strengthened as outlined in the approved policy and the Observatory’s Data Management Plan. More than $80\,000$ cosmic-ray events above $10^{17}$...
The HESS Galactic Plane Survey (HGPS), published in 2018, presented a decade of very-high-energy (VHE) gamma-ray observations along the Galactic plane. This study was accompanied by the release of several maps in FITS format, offering a detailed view of the region. The flux upper-limits from these HGPS maps can be compared to the high-energy (HE) spectra of sources catalogued by the Fermi-LAT...
The baryon asymmetry observed in our universe today, suggests that the baryon number (B) must be violated and theories Beyond the Standard Model are necessary to explain the early evolution of our universe [1]. The observation of a B-violating process has been elusive so far, however, the n-$\bar{\text{n}}$ oscillation process has the potential to be measured in the next decade [2]. This would...
After atmospheric muons enter the sea, a decreased muon count is observed at the bottom of water. Muon count is inversely proportional to the density of water which can be measured by counting muons at the bottom. Mixed Layer (ML) in Oceans is defined as the less dense upper region of the water column where turbulent mixing occurs. Mixed Layer Depth (MLD) is the depth of this region and shows...
This paper proposes an approach that improves the accuracy of reconstructing the primary energy at ground-based cosmic-ray stations. The problems of determining the primary energy caused by large fluctuations in the development of an extensive air shower are considered in detail.
The information obtained during the study of EAS is of a very indirect nature, since the first interaction of a...
FPGAs are widely deployed on high-energy astrophysics telescopes to read out sensor data from front-end electronics. To support continuous data streams or high trigger rates, FPGA logic may be employed to process raw sensor readout values, reducing the volume of data transmitted, processed, and stored by downstream CPU-based computational platforms. Traditionally, this logic is specified in a...
Prompt emission of GRB is believed to be produced from electrons accelerated up to non thermal energies in the internal shocks. This emission peaks in the keV-MeV energy band, but a high energy (HE; 0.1<E<100 GeV) component is theoretically expected. While photons in the very high energy (VHE; E>20GeV) domain have been detected by Imaging Atmospheric Cherenkov Telescopes in recent years,...
Gamma-ray observatories must efficiently distinguish gamma-ray-induced showers from the abundant background of hadronic showers. The shape of the lateral signal distribution offers crucial information for this task. Sb is a key observable that characterizes the shape of the lateral signal distribution. It is computed using the signal and position of each triggered detector, along with a free...
The Dark Matter Particle Explorer experiment allows for $\gamma$-ray detection up to TeV energies, with an unprecedented energy resolution of about 1\%, which makes it a unique instrument for $\gamma$-ray physics at these energies. A deep-learning tool for track reconstruction has already been developed for electrons and ions. We used this tool on $\gamma$-ray samples to assess its efficiency...
A series of intense solar flares occurred in May 2024. Among other effects, a remarkable Forbush decrease in the cosmic ray flux was observed on the Earth. This event was observed by neutron and muon detectors installed at the Svalbard, in a high latitude site, characterized by a weak geomagnetic shielding. For this analysis we employed at Ny-Ålesund three scintillator-based muon telescopes of...
The PHeSCAMI project (Pressurized Helium Scintillating Calorimeter for AntiMatter Identification) aims to identify anti-deuterium in cosmic rays by exploiting the existence of delayed annihilations (~μs) expected in a pressurized helium target. The technique relies on measuring the helium scintillation signal (80 nm), which requires a two-stage WLS (Wavelength Shifter) conversion. This...
The interplanetary propagation of solar energetic particles (SEPs) can be influenced by large-scale interplanetary structures. The Heliospheric Current Sheet (HCS) is one such large scale structure that persists in the interplanetary solar wind background. Observations show that the time profile, onset time and other characteristics of the SEP flux change significantly after crossing the HCS....
The hybrid detection approach in astroparticle physics has been successfully employed in cosmic-ray experiments and is currently being explored by gamma-ray observatories like LHAASO. We present a study on the hybrid detection concept for the future Southern Wide-field Gamma-ray Observatory (SWGO), integrating multiple Cherenkov telescopes represented in the analysis by Single-Mirror...
IceTop, the km² surface array of the IceCube Neutrino Observatory at the South Pole, is sensitive to air showers of all primary particles, including gamma rays. In particular, in the PeV energy range, the combination of IceTop and IceCube’s deep optical detector provides excellent gamma-hadron separation. Almost all air showers induced by cosmic-ray protons and heavier nuclei in this energy...
The CALorimetric Electron Telescope (CALET), operating aboard the International Space Station since October 2015, is an experiment dedicated to high-energy astroparticle physics. The primary scientific goal of the experiment is the measurement of the electron+positron flux up to the multi-TeV region. At such high energies, proton contamination - coupled with limited statistics - is the main...
The Cubic Kilometre Neutrino Telescope - KM3NeT - is subject to an intense flux of atmospheric muons, even at the bottom of the Mediterranean Sea. These atmospheric muons are created by the collisions of cosmic rays with nuclei of the upper atmosphere and their subsequent interactions, and as such, serve as probes of cosmic ray physics. The KM3NeT/ARCA and KM3NeT/ORCA detectors are located...
Radio astronomy has emerged in the last decade as a promising approach for detecting Weakly Interacting Massive Particles (WIMPs) annihilation and decay signatures, particularly due to its capability to distinguish and detect diffuse emission.
Local Group dwarf spheroidal galaxies (dSphs) are ideal targets for these searches due to their high dark-matter content and low astrophysical...
The upper 20 meters of the polar ice sheets exhibit significant density inhomogeneity, causing significant fluctuations in the in-ice signal amplitude as a function of depth. Understanding these effects is crucial for radio-based ultra-high-energy neutrino searches using ice as a detection medium. We present in-situ measurements of density ($\rho$) and refractive index ($n$) in the upper 13...
The Ultra-High Energy Cosmic Rays (UHECRs) are nuclei carrying the highest energy ever measured on Earth. The first particle with an energy above 10^{20} eV was already observed in the 1960s. But, after 60 years of observations, the sources of UHECRs remains uncertain. To tackle this unresolved question, the Pierre Auger Observatory, the largest observatory ever built, has recorded the...
Detection of extensive air showers with radio antennas is an appealing technique in cosmic ray physics. However, because of the high level of measurement noise, current reconstruction methods still leave room for improvement. Furthermore, reconstruction efforts typically focus only on a single aspect of the signal, such as the energy fluence or arrival time. Bayesian inference is then a...
We present predictions from phenomenological models to study the transverse momentum spectra of identified hadrons in Au+Au collisions at a center-of-mass energy of 7.7 GeV, as measured by the STAR detector at the Relativistic Heavy Ion Collider. This analysis evaluates the performance of Monte Carlo models Pythia8.3 and EPOS (EPOS4 and EPOSLHC) by comparing their predictions with experimental...
We present our new model of very-high-energy (VHE) cosmic rays incorporating discrete distributions of cosmic-ray sources, allowing for a more realistic description of our Galaxy. Using our model, we investigate two diffusion regimes, namely homogeneous and inhomogeneous diffusion around the cosmic-ray sources, and show how to constrain the birthrate of PeVatrons supernova remnants (SNRs). We...
The Antarctic Demonstrator for the Advanced Particle-astrophysics Telescope (ADAPT) gamma-ray/cosmic-ray instrument serves as a precursor to the proposed APT mission. This mission is designed to improve sensitivity in the MeV-TeV gamma-ray range by an order of magnitude compared to current missions and is optimized for dark-matter and multimessenger research. The ADAPT instrument uses...
Blazars are a special subclass of active galactic nuclei (AGNs) characterized by a relativistic jet aligned at a small angle to the observer’s line of sight. Their spectral energy distributions (SEDs) are dominated by non-thermal emission and exhibit two broad, distinct components: a low-energy component, spanning from radio to UV or X-ray wavelengths, and a high-energy component, extending...
The Dark Matter Particle Explorer (DAMPE) has made significant progress in measuring cosmic ray nuclei. These new measurements are pivotal in advancing our understanding of the origins and propagation mechanisms of cosmic rays. The Bismuth Germanium Oxide (BGO) calorimeter plays a crucial role in these measurements, particularly in the precise determination of cosmic ray fluxes. However, for a...
The IceCube Neutrino Observatory studies cosmic-ray initiated extensive air showers (EASs) using the IceTop surface array, which is sensitive to the electromagnetic and low-energy muonic components of EASs. The two components are reconstructed on an event-by-event basis by simultaneously fitting separate lateral distribution functions (LDFs) for the electromagnetic and muonic components of...
The LACTEL project proposes the development of a Water Cherenkov Detector Array (WCDA) for cosmic electron and gamma-ray observations, through the study of Extensive Air Showers (EAS).
It aims to improve gamma-ray and electron observations above 10 TeV, suppressing the hadron background through muon tagging.
Additionally, the project will also serve as a multidisciplinary platform for...
The interpretation of EAS data depends on the hadronic interaction model, which faces theoretical and experimental uncertainties that significantly impede the study of cosmic ray composition. To evaluate the reliability of these models, it is vital to examine the lateral density distributions of muons and electrons, as they are sensitive to hadronic interactions that occur during EAS...
The existence of fractionally charged particles (FCP) is foreseen in extensions of or beyond the Standard Model of particle physics. The FCP is commonly assumed to be a kind of heavy lepton-like particle which is searched in cosmic-rays by underground and space experiments. The DArk Matter Particle Explorer (DAMPE) is a space telescope launched on December 17th, 2015 and has taken data since...
CTA 1 is a shell-type supernova remnant (SNR) with a central pulsar wind nebula (PWN), visible at very-high-energy (VHE) from 50 GeV to 100 TeV in a moderately extended emission region. While general consensus concludes the VHE emission originates from relativistic leptons accelerated by the PWN and undergoing inverse Compton scattering, questions remain about electron escape and propagation,...
The fast variability of very-high energy (VHE) sources such as pulsars, gamma-rays bursts (GRBs) or flares of active galactic nuclei (AGN) can be used to detect or constrain Lorentz invariance violation (LIV) by measuring lags in the arrival time of VHE photons. However, an important source of uncertainty arises from processes within the source that may induce intrinsic photon delays....
We present a toolkit developed with students at the LAMBDA laboratory at Buenos Aires University, which facilitates data acquisition, calibration, and reconstruction of particle events. We designed this kit around the Sony IMX477 CMOS sensor, an affordable off-the-shelf sensor priced at around 50 USD and easily integrated with a Raspberry Pi. This camera enables, for example, the visualization...
The GRAPES-3 experiment is a ground-based extensive air shower array which consists of approximately 400 closely packed plastic scintillator detectors and a large area muon telescope. Estimating the number of associated muons created in an air shower is crucial to understand the properties of primary cosmic rays. The GRAPES-3 muon telescope(G3MT) records these secondary muons, however, the...
The High-Altitude Water Cherenkov (HAWC) Observatory comprises 300 water Cherenkov detectors, each equipped with four photomultipliers, located on the Volcán Sierra Negra in Mexico at 4,100 masl. This observatory can detect gamma rays in an energy range from 300 GeV to 100 TeV and cosmic rays from 100 GeV to 1 PeV. One of HAWC’s primary challenges is characterizing air showers and estimate...
Neural networks (NNs) have a great potential for future neutrino telescopes such as IceCube-Gen2, the planned high-energy extension of the IceCube observatory. IceCube-Gen2 will feature new optical sensors with multiple photomultiplier tubes (PMTs) designed to provide omnidirectional sensitivity. Neural networks excel at handling high-dimensional problems and can naturally incorporate the...
Galaxy clusters host tangled magnetic fields, shaped by primordial seeds and amplified through cosmic dynamo action. While these fields stabilize over time, merger-driven shock waves can trigger magnetic amplification, sustained over the shock lifetime. Diffuse non-thermal emission and polarization measurements from radio relics indicate a magnetisation of the intracluster medium due to merger...
The IceCube Neutrino Observatory is a cubic-kilometer Cherenkov array deployed in the deep, glacial ice at the geographic South Pole. An important feature of the instrumented ice are undulations of layers of constant optical properties over the footprint of the detector. During detector construction, these layers were mapped using stratigraphy measurements obtained from a stand-alone laser...
We report on the cosmic ray mass composition measured by the Telescope Array Low-energy Extension (TALE) hybrid detector. The TALE detector began hybrid operations in 2017 after a surface detector (SD) array of 80 scintillation counters, 40 detectors with 400 m spacing and 40 with 600 m spacing, was added in front of the Middle Drum telescope station which includes 10 high-elevation...
To investigate the mechanism responsible for the steepening beyond the knee, it is necessary to measure the energy spectra of individual nuclear elements. The Tibet ASγ experiment is designed specifically to observe the shower maximum around the energy of the knee. It employs a high-density air-shower array (Tibet-III) to measure the charged particles, designated by the sum of charged particle...
Measurements of the cosmic ray flux at large latitudes, close to the Arctic Circle, were carried out in the last years by the Extreme Energy Events (EEE) Collaboration on board of a small boat, sailing from 66° to 82° N. A compact, scintillator-based, cosmic ray telescope was employed during such campaign. These measurements were later complemented at smaller latitudes, across Europe, from 35°...
The IceCube Neutrino Observatory has observed astrophysical neutrinos with energies ranging from a few TeV to multiple PeV. To extend the energy range beyond 10 PeV, we combine through-going tracks from the northern sky, high-energy starting tracks, contained cascades and uncontained cascades from the entire sky. This extension is critical for testing models that predict a common origin for...
We describe the design, construction and operation of a compact cosmic rays (CRs) telescope of TRASGO (TRAck reconStructinG bOx) type, consisting of four resistive plate chambers (RPCs), located in Puebla City, Mexico, at a latitude/longitude of 18° 59' 56" N/98° 11' 41" W. and 2100 m.a.s.l. This telescope allows the detection of isolated muons with good angular resolution under the use of...
In underground astrophysics experiments such as neutrino, dark matter, and double beta decay searches, it is important to use the ultra-low radioactive impurities in the material of the detectors. We have been developing the gaseous TPC with the μ-PIC (or micropattern gaseous detectors: MPGD) and optics to measure the emissivity of alpha particles from the material surface in a low radioactive...
DAMPE is a space-based calorimeter specifically designed for the detection of cosmic electrons, gamma-rays, and nuclei. It has been launched in December 2015, and has been operating smoothly for over nine years, during which it has recorded more than 1.6 billion events. Among all medium-mass elements, the carbon-nitrogen-oxygen (CNO) group has the largest abundance. We have utilized 9 years of...
Nuclear fragmentation cross sections are important parameters for the
modeling of the propagation of cosmic rays through the Galaxy. These
types of measurements at energies above 10A GeV are part of the
NA61/SHINE experiment’s cosmic-ray program. The high quality of the
experiment detector was proved during pilot studies conducted
in 2018. The second measurement campaign was carried out...
In this paper, a method is proposed that improves the accuracy of energy determination in direct measurements of cosmic rays with energies of TeV and higher.
The problems of determining the primary energy using a thin ionization calorimeter are considered in detail. They are caused by large fluctuations in shower development, a decrease in the statistics of the analyzed events with increasing...
The miniTRASGO is a compact and cost-effective secondary charged cosmic ray detector designed for studies in solar activity, cosmic rays, and atmospheric physics. Utilizing Resistive Plate Chambers (RPCs), it ensures stable detection rates and high sensitivity, as demonstrated by the measurement of Forbush Decreases in March and May 2024 at the Madrid station ($40.4^\circ\mathrm{N},\ 7...
Log-Periodic Dipole Array (LPDA) antennas are widely used in radio detection experiments for ultra-high-energy (UHE) extensive air showers (EAS), such as TAROGE-M and ARIANNA-HCR in Antarctica, due to their simple design, high gain across a broad frequency band, and strong wind resistance. However, icing on the antenna alters its response, introducing systematic effects that degrade detector...
Coronal Mass Ejections (CMEs) are large-scale eruptions of plasma and magnetic fields from the Sun, capable of significantly impacting Earth's magnetosphere and triggering geomagnetic storms. These storms can disrupt power grids, satellite operations, and navigation systems. Enhancing our understanding of CME propagation and their interaction with the solar wind is crucial for improving space...
IceCube has detected a diffuse flux of high-energy neutrinos of astrophysical origin. Although several neutrino sources have been identified, they contribute only a small fraction of the total flux, leaving most of its origin unresolved. We present a novel approach to modelling a diffuse high-energy neutrino flux from star-forming activity using SIMBA, a state-of-the-art cosmological...
Neutron monitors are crucial ground-based instruments for studying cosmic rays, requiring precise response function modeling to properly interpret flux variations. A new boron trifluoride (BF₃) proportional counter tube from LND Inc. maintains the identical geometry, gas volume, and pressure of the BP28 counter, a standard in NM64 neutron monitors, while differing in anode wire and cathode...
The IceCube Neutrino Observatory at the South Pole detects neutrinos of astrophysical origin via their interactions with ice. The main array is optimized for the detection of neutrinos with energies above 1 TeV. A much smaller infill array, known as IceCube DeepCore, extends the sensitivity down to a few GeV. Neutrinos observed in both parts of the detector are used for astrophysical-source...
Atmospheric muons are important probes for studying primary cosmic rays and extensive air showers. Additionally, they constitute a significant background for many underground and deep-sea neutrino experiments, such as TRopIcal DEep-sea Neutrino Telescope (TRIDENT). Understanding the muon flux at various depths in the deep sea is essential for validating TRIDENT simulations and guiding the...
We explore the neutrino energy spectrum and directional distribution in the energy range of 1 MeV to 10 TeV on Moon. The lunar surface has a variety of neutrino sources, including those generated by cosmic rays interacting with the lunar regolith (referred to as lunar regolith neutrinos), geoneutrinos from decays of natural radioactive elements, Earth's atmospheric neutrinos, solar neutrinos,...
We perform extensive test-particle simulations of cosmic rays (CRs) propagating in synthetic (homogenous and isotropic) turbulent magnetic fields using the Monte Carlo code CRPropa. Applying multiple numerical methods in the literature, we compute the coefficients of the diffusion tensor as a function of particle rigidity and turbulence level, i.e. the ratio between the root mean square of the...
The COR simulation engine is a tool devoted to evaluating cosmic ray trajectories in Earth's magnetosphere. It is part of the COR System, available at https://cor.crmodels.org/, and it also functions as a standalone command line tool. The former tool was published in 2022. We report the new version of the tool status with improved performance, precision, new functions/features, and refactored code.
Do neutrinos of different flavors have preferred directions of travel? If they do, it would imply a violation of Lorentz invariance, a cornerstone of modern physics. This would manifest as "flavor anisotropies"---differences in the arrival-direction distributions of astrophysical neutrinos of different flavors at Earth. In beyond-Standard-Model theories, these effects grow with neutrino...
Clouds not only play a crucial role in weather dynamics but are also a key factor influencing cosmic ray detection. The presence of clouds increases the absorption of Cherenkov light, thereby affecting cosmic ray observations. Moreover, the variation of clouds over the Tibetan Plateau(TP) has a significant impact on radiation balance and even the global water cycle. This study utilizes the...
The detection of side-scattered ultraviolet light from spaceborne lasers with fluorescence telescopes of cosmic ray observatories offers unique opportunities for systematic studies of the aerosol content of the local atmosphere. It also enables the validation of the optical calibration of the telescopes. Additionally, these observations provide valuable ground-based monitoring of the...
LHAASO J2027+3657 is an ultra-high-energy (UHE) gamma-ray extended source discovered by LHAASO in the Cygnus region. No significant very-high-energy (VHE) emission has been detected from this source, and ground-based facilities like H.E.S.S. and HAWC have not observed it either, making the origin of its emission especially interesting. In this study, we use the latest LHAASO data to perform a...
CTB 109 is a middle-aged shell-type supernova remnant (SNR) with bright thermal X-ray emission. The gamma-ray emission of CTB 109 exhibits a center-bright morphology, which is very consistent with its thermal X-ray emission rather than the shell-type structure in the radio band. The GeV gamma-ray spectrum shows a significant spectral curvature at a few GeV. In this work, we describe the...
Recent studies, supported by updated hadronic interaction models, suggest that the mass composition of ultra-high-energy cosmic rays may be heavier than previously assumed. This has significant implications for source identification, as the deflections of the Galactic magnetic field (GMF) are larger for heavy primaries than for lighter ones at the same energy. In this work, we assume that...
Observing and monitoring low‐energy charged particles—from sub‐MeV up to tens of MeVs—has become increasingly important for several reasons, impacting various fields of science. These range from radiation protection and the study of magnetosphere–lithosphere interactions to investigations of space weather and the interplay between the heliospheric environment and the magnetosphere. To address...
The Small-Sized single-mirror Telescopes (SST-1Ms) are designed to observe the gamma rays within the TeV range. The two 4-meter diameter Davies-Cotton SST-1M telescopes are operated at the Ondřejov Observatory of the Astronomical Institute of the Czech Academy of Sciences near Prague. The telescopes use White Rabbit for time synchronization, enabling the detection of coincident events in...
The Hybrid Elevated Radio Observatory for Neutrinos (HERON) is designed to target the astrophysical flux of Earth-skimming tau neutrinos at 100 PeV. HERON consists of multiple compact, phased radio arrays embedded within a larger sparse array of antennas, located on the side of a mountain. This hybrid design provides both excellent sensitivity and a sub-degree pointing resolution. To design...
Recent hundred PeV muon track in downward in downward horizons of ARCA km3 array detector surpprised most of the observer. This UHE event, if confirmed, might be the first signature of UHECR secondaries . The photon pion GZK cut off on proton or the photo-nuclear disintegration may be the source of it. However the presence of such a rare and huge event in such a small and new detector...
The goal of the Stereoscopic Water Cherenkov array ( SWCDA ) project is to observe high-energy gamma rays in the 100 GeV-10 TeV energy region. The detector is designed to complement other current ground-based experiments. It will greatly improve the sensitivity of gamma-ray observations in the 100GeV-10 TeV range. By the end of 2024, we have built a prototype of 100 m^2 inside the Tibet...
The Advanced Particle-astrophysics Telescope (APT) is a mission concept for a space-based gamma-ray telescope whose capabilities include prompt localization of gamma-ray bursts (GRBs) to support multi-wavelength and multi-messenger astrophysics. We describe the current state of our GRB localization pipeline aboard APT's balloon-borne prototype, the Antarctic Demonstrator for APT (ADAPT). We...
The scintillating FIber Tracker (FIT) has been designed as a tracking detector for the upcoming High Energy cosmic-Radiation Detection (HERD) facility. The FIT combines excellent angular resolution with precise charge reconstruction measurements for cosmic-rays detection. The tracker consists of multiple tracking planes made of fiber mats, arranged in two orthogonal directions, and read out...
Next-generation air-shower detectors, such as the Global Cosmic Ray Observatory (GCOS) and the Probing Extreme PeVatron Sources (PEPS) experiment, will face many challenges in terms of detector design and construction. A key factor in improving the sensitivity to ultra-high energy gamma rays and to the mass composition of ultra-high energy cosmic rays is the ability to measure the muonic...
We discuss the self-induced confinement of ultra-high-energy cosmic rays
(UHECRs) near their sources, as driven by the excitation of the Non-Resonant Streaming Instability (NRSI) in the intergalactic medium (IGM).
For a standard source spectrum ∝ E$^{−2}$, the current associated with the escaping UHECRs excites perturbations through NRSI (also known as the Bell instability), leading to Bohm...
Until now, several space experiments have observed a bump structure near 10 TV of rigidity in the primary cosmic ray spectrum. In this work, the energy spectrum measurement of sub-iron nuclei (Sc, Ti, V, Cr, Mn) with the DAMPE satellite is reported from 300 GeV up to 2 PeV , thus covering the energy range where a bump structure in the primary cosmic rays has been detected. By Providing the...
Only three TeV-emitting pulsars are known to date, two of which — the Vela Pulsar and PSR J1509 — exhibit a multi-TeV emission component distinct from their GeV emission spectrum. While the origin of the GeV component, whether due to curvature radiation in gaps or synchrotron radiation in the current sheet, remains debated, the multi-TeV emission is most likely produced by inverse-Compton...
The Astroparticle field is actively searching for the origin and the nature of the Ultra-high energy cosmic rays from deep within the Universe as they carry the information from those regions and might also hint on possible new physics. This talk reports on the overall design and the ongoing construction and calibration of DUCK (Detector system of Unusual Cosmic-ray casKades), a new...
Atmospheric neutrinos and muons, produced from cosmic-ray-induced air showers, are one of the dominant backgrounds for astrophysical neutrino detections. The flux with energy below 100 TeV is dominated by muons and conventional atmospheric neutrinos produced by pion and kaon decays. In contrast, their prompt counterparts, from decays of short-lived charm hadrons, are predicted to contribute at...
It is generally accepted that in supernova remnants (SNRs), charged particles are accelerated to cosmic-ray energies through the mechanism of diffusive shock acceleration (DSA). The most compelling observational evidence supporting this model is related to the electron component: relativistic electrons with energies of about $\sim 10$ GeV, accelerated in SNRs, generate nonthermal radio...
Gamma-ray experiments like BATSE, the Fermi GBM and LAT, and SWIFT have provided a wealth of data on gamma-ray bursts (GRBs), but prompt observations of multiwavelength counterparts of short bursts have been limited. To facilitate such observations, this work describes progress toward production of real-time GRB alerts that include detailed likelihood maps computed entirely aboard a gamma-ray...
Recently, the technique of detecting high-energy particles using water Cherenkov radiation has achieved great success in ground-based cosmic ray observation experiments. For example, the Tibet ASγ experiment, the HAWC experiment, and the LHAASO experiment. However, research on the basic performance of water Cherenkov detectors is still lacking. In this work, the fundamental performance of the...
KM3NeT is a European research infrastructure developing second-generation multi-km³ neutrino telescopes on the Mediterranean Sea floor. It consists of two main sites targeting complementary neutrino energy regimes: KM3NeT/ARCA for TeV-PeV neutrinos and KM3NeT/ORCA for GeV- few TeV neutrinos.
Within the KM3NeT collaboration, an automated system continuously monitors and analyzes real-time...
The KM3NeT Collaboration is incrementally building and operating two underwater Cherenkov neutrino telescopes, made of modular units named DOMs (for Digital Optical Module), each one hosting 31 photomultipliers, and arranged in strings of 18, named DUs (for Detection Unit) anchored to the sea bed and kept in tension by a buoy. One telescope, named ORCA, will consist of a single building block...
High-energy atmospheric muons are the prevalent events detected by deep under-water/ice neutrino telescopes. Understanding their properties at sea level is crucial for accurately interpreting the observed signals. We present in this work results for the calculation of the flux and charge ration of atmospheric muons at sea level above 100 GeV. We use the Monte Carlo code CORSIKA for our...
Dark matter (DM) constitutes 27% of the universe, but its precise nature remains unknown. Several DM particle candidates were suggested, such as the Weakly Interacting Massive Particles (WIMPs), which can annihilate and create gamma rays. Our research focuses on detecting these gamma rays, specifically around Intermediate Mass Black Holes (IMBHs). The strong gravitational potential of IMBHs is...
KM3NeT/ARCA is a very large-volume neutrino telescope currently under construction deep underwater in the Mediterranean Sea. Although primarily designed to search for high-energy neutrinos from astrophysical sources, this detector also has the potential to probe cosmic rays in the TeV-PeV energy range - an advantage made possible thanks to the atmospheric muons, which constitute the...
Gamma-ray bursts (GRBs) are among the most energetic phenomena in the universe, attracting significant interest not only in astronomy but also in the field of particle physics.
GRB 221009A is the most energetic gamma-ray burst ever observed. A possible related phenomenon was reported as an increase in the muon detection rate by the Yangbajing Muon Telescope, which is installed at the...
The High-Altitude Water Cherenkov (HAWC) observatory was designed to study gamma-ray sources in the energy range between a few hundred GeV up to few hundred TeV. It is composed of 300 Water Cherenkov Detectors (WCDs) that cover a surface of approximately 22,000 m$^2$, at 4100 m. a.s.l. In this study, we use the HAWC WCDs as a very large horizontal particle tracker, searching for horizontal...
Numerous experiments search for Ultra-High Energy Neutrinos by instrumenting the upper 200 meters of the polar ice sheet with antennas to detect neutrino-induced radio emission, including Askaryan radiation and radar reflections off the ionization trail left in the wake of the particle cascade. This places them within or immediately below the region of compacted snow, known as firn, which is...
CORSIKA 8 is a modern Monte-Carlo simulation framework for particle showers in air and dense media. The calculation of shower-induced radio-emissions is a key element of the code, relevant for experiments targeting radio detection of cosmic rays and neutrinos.
In this contribution, we will report on the unique capabilities of CORSIKA 8 to simulate the radio emission from showers developing...
Innovative science communication is key to engaging the public with complex topics such as astroparticle physics. As part of the Italian PRIN 2022 funding initiative, we are developing SkyNET-scape Room, an interactive escape room designed to introduce participants to the main messengers of the high-energy universe, namely cosmic rays, gamma rays, and neutrinos.
The experience is structured...
Gamma-ray emission in the GeV-TeV range from the solar disk (observed by Fermi-LAT and HAWC) is likely to arise from collisions of galactic cosmic rays (GCRs) with solar atmospheric plasma. We model the photo-/chromospheric magnetic field with a static, laminar structure of open field lines in the chromosphere increasingly braiding near the solar surface, with a typical scale height of 0.01...
We propose to develop future detectors to verify the MSW effect on the oscillation in solar neutrinos. We have focused on inorganic scintillation crystals, which have a potential to be high energy-resolution detectors because their light yield is higher than that of liquid scintillation or water Cherenkov light. However, the background noise from radioactive impurities in the crystal and...
Particle acceleration inside the solar atmosphere remains not fully understood. Although several mechanisms have been proposed, a widely accepted framework is still lacking. Understanding these processes is crucial not only for studying particle acceleration itself but also for providing deeper insights into the solar explosive events. The most natural approach to studying particle...
Polarization measurements are essential in astrophysics and nuclear physics, offering profound insights into fundamental physical processes. In astrophysics, the polarization of gamma rays provides critical information about high-energy astrophysical phenomena such as black holes, neutron stars, and gamma-ray bursts, helping to explore the radiation mechanisms and the structure of the...
Lorentz invariance violation is a feature of several quantum gravity models in which Lorentz symmetry is broken at high energies, leading to potential changes in particle behavior and interactions. In this study, we investigate vacuum Cherenkov radiation, a reaction in which an electron spontaneously emits a photon. This process, forbidden when considering unbroken Lorentz symmetry, is a...
The IceCube Observatory comprises a cubic-kilometer particle detector deep in the Antarctic ice and the cosmic-ray air-shower array IceTop at the surface above. Previous analyses of the cosmic-ray composition have used coincident events with IceTop detecting the electromagnetic shower footprint, including GeV muons, while the sensors submerged in the ice measure the TeV muons from the same...
We present a comprehensive study addressing pile-up effects in single photoelectron counting with multi-anode photomultiplier tubes (MAPMTs) equipped with the SPACIROC-3 ASIC. Extended dead time in the electronics causes saturation and quenching of the counting rate, an effect we counter by inverting the saturation curve once the double pulse resolution is determined. Our work combines...
The SST-1M telescopes are a pair of Imaging Atmospheric Cherenkov Telescopes (IACTs) that have been operating at the Ondřejov Observatory (500 m a.s.l.) in the Czech Republic since 2022. Optimized for detecting gamma rays in the energy range 1-300 TeV, they are capable of performing both mono and stereo observations. Despite challenging atmospheric and geographical conditions, SST-1M has...
The Dark Matter Particle Explorer (DAMPE) has been operating smoothly in a sun-synchronous orbit with an altitude of 500 km and an inclination angle of 97.4 degree for more than 9 years. The observation scanning the entire sky for more than 18 times facilitate a continuous probing of the anisotropy in the arrival directions of the cosmic rays with increasing sensitivity. In this poster we show...
TAx4 is an extension of the detection area for ultra-high-energy cosmic ray observations in the Telescope Array experiment. In the TAx4 surface detector analysis, a lateral distribution function (LDF) is used to describe particle density as a function of distance from the air shower axis. The current TAx4 analysis assumes a symmetric LDF around the shower axis; however, this assumption may not...
In the search and measurement for cosmic antiparticles, as one of the benchmarks for the GRAMS experiment, understanding of antiproton reactions in a liquid argon TPC with high-statistics is a vital research milestone. The identification of particles and antiparticles relies on the annihilation of antiprotons, which stop in liquid argon and interact with argon nuclei, producing multiple...
Solar cycle 25 is reaching its period of maximum activity. Associated to this, gigantic coronal mass ejection sweep cosmic rays in the Interplanetary medium, producing a sudden decrease in the cosmic-ray intensity is observed at Earth (and in space). These so called Forbush decreases (FD) can be detected on the surface of Earth at various geomagnetic cut-off rigidities using Neutron Monitors...
We investigate the effects of Lorentz invariance violation (LIV) on photon interactions, considering both intergalactic propagation (Breit-Wheeler process) and atmospheric interactions (Bethe-Heitler process). By incorporating LIV into the theoretical framework, we analyze how it modifies key quantities such as the cross section, threshold energy, and mean free path of photons traveling...
A significant challenge encountered by ground-based gamma-ray observatories is the substantial quantity of cosmic-ray particles that trigger detections. Therefore, it is crucial to implement techniques that can distinguish and separate gamma-ray showers from cosmic-ray showers. The Southern Wide-field Gamma-ray Observatory (SWGO) will be an array of water Cherenkov detectors, currently planned...
The Forbush decrease (FD) is a short-term decrease in cosmic ray flux observed during the passage of transient interplanetary disturbances such as interplanetary counterpart of coronal mass ejection (ICME) and Co-rotating interaction regions (CIR). On 8-13 May 2024, multiple ICMEs erupted from active region AR 13664. On May 10, 2024, after the arrival of ICME shock at 17:04 UT, deep FD is seen...
In this presentation we report the study for searches for high-energy astrophysical electron neutrinos ($ν_e$) above 10 GeV using an optimized selection criterion in Super-Kamiokande (SK).
Potential sources of high-energy astrophysical neutrino include galactic plane, active galactic nuclei such as NGC 1068, as well as specific types of supernovae with structure of circumstellar material....
Supernova remnants (SNRs) are among the primary sources of cosmic rays (CRs) in our galaxy and observations of the pion bump by AGILE and Fermi-LAT support their role in CR production. Recently LHAASO detected ultra-high-energy (UHE, > 100 TeV) γ-rays from several Galactic sources, including some SNRs. However, existing theoretical models predict that they can accelerate CRs to PeV energies...
The China Seismo-Electromagnetic Satellite (CSES) is a space mission developed by the Chinese National Space Administration (CNSA) together with the Italian Space Agency (ASI), to investigate the near-Earth electromagnetic, plasma, and particle environment. The first satellite, CSES-01, was launched in February 2018. One of the main payloads on board the CSES-01 satellite is the High-Energy...
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment primarily focusing on determining the mass ordering of neutrinos through the use of reactor antineutrinos. The JUNO detector is equipped with a 20-kiloton liquid scintillator target, monitored by 17,612 20-inch photomultiplier tubes (PMTs) and 25,600 3-inch PMTs. Construction of the JUNO detector was...
The Large Volume Detector (LVD) at the INFN Gran Sasso National
Laboratory, Italy, is a neutrino observatory designed to study low energy neutrinos
from gravitational stellar collapses. The detector features 1000 tons of liquid
scintillator and is sensitive with full efficiency to core-collapse and failed
supernovae occurring in the Galaxy through neutrino burst detection.
In this...
The Askaryan Radio Array (ARA), located near the geographical South Pole, is one of the first two experiments designed to detect ultra-high energy neutrinos through the Askaryan effect. In this phenomenon, interactions of these neutrinos within dense media like ice generate coherent radio pulses. Operating within a radio frequency bandwidth of 150 to 850 MHz, ARA is deployed 100-200 m deep in...
We present an analysis of the time-dependent modulation of galactic cosmic rays near Earth, with a focus on the cosmic proton flux and polar field. Using data from the Alpha Magnetic Spectrometer (AMS) and the Wilcox Solar Observatory, we identify a significant time-lagged relationship between the observation of two missions. Our model incorporates a weighted magnetic field parameter to...
The understanding of micro-quasars is one of the frontiers of high energy astrophysics. Their models are based on a capturing mass by compact objects , Neutron star (NS) or in general Black Hole (BH), with a nearby spiraling binary companion star. The companion star mass usually feeds an accretion disk around the NS or the BH. The in-falling mass also fuels a precessing X and gamma jets,...
Dark100 is a planned array of five telescopes, using the Panoramic Search for Extraterrestrial Intelligence (PANOSETI) telescope system. It will operate as an imaging atmospheric Cherenkov telescope array, with a telescope design and array layout optimized for accessing gamma rays with tens of TeV to PeV energies. The science goals of Dark100 include the search for ultra-heavy dark matter,...
The SiPM camera for the LACT project divides 1616 pixels into 101 sub-modules to facilitate the development, testing, assembly, and maintenance of detector modules. Each module consists of a 4×4 pixel array and a 16-channel Front-End Electronics (FEE) board. The FEE board integrates two main functionalities: 1) it shapes and amplifies the analog pulses from the SiPMs into narrow pulses and...
The LACT project will deploy 32 atmospheric Cherenkov telescopes with a diameter of 6 meters at Haizishan, Daocheng County, Sichuan Province, to conduct detailed structural measurements of multiple ultra-high-energy gamma-ray sources discovered by LHAASO. The cameras are installed on the optical focal plane of the telescopes to image the Cherenkov light reaching their surfaces. We will...
We present the first beta version of code to simulate cosmic ray acceleration on supernova remnants shock. A model built in Python provides spectra of accelerated cosmic rays by numerical solutions of Parker equations based on the SDE method for interstellar space and a model for exploding supernovae.
The KM3NeT observatory hosts two undersea neutrino telescopes, ARCA and ORCA, located at two abyssal sites of the Mediterranean sea. The detectors consist of a 3D array of optical modules, each housing 31 3-inch photomultiplier tubes to detect Cherenkov light emitted by charged particles produced in neutrino interactions in water. Although still under construction, both detectors are already...
The mass independent energy reconstruction of cosmic rays is crucial for understanding their origin, acceleration, and propagation. Precise measurement of the primary energy can also lead to better mass classification and could enable energy dependent anisotropy maps for individual elements. The GRAPES-3 experiment located in Ooty consisting of 400 scintillator detector array placed 8 m apart...
NectarCAM is a Cherenkov camera which is going to equip the Medium-Sized Telescopes (MST) of the northern site of the Cherenkov Telescope Array Observatory (CTAO).
This contribution presents the hardware design of NectarCAM. The camera has a modular design, with 265 identical modules of 7 pixels, installed in a module holder and cooled by airflow. The modules are responsible for the...
The Zirè experiment is part of the NUSES space mission, proposed by the Gran Sasso Science Institute (GSSI) in collaboration with many Institutes and Universities from Europe and US. Zirè science goals include the measurements of charged particles and light nuclei from few up to hundreds of MeVs, for the study of low energy CRs, space weather phenomena and possible...
Multi-wavelength and multi-messenger astrophysics have experienced rapid growth over the past decade, seeking a complete picture of different cosmic phenomena. Transient sources, in particular, benefit from the input of multi-messenger observations, offering complementary perspectives on the same event while maximizing the detection probability of a rapidly fading signal.
In this context,...
The High Energy Light Isotope eXperiment (HELIX) is a balloon-borne superconducting magnet spectrometer designed to measure abundances of light cosmic-ray isotopes. HELIX which undertook its first engineering flight in the Spring of 2024, identifies cosmic rays through measurements of their velocity, rigidity and charge. These measurements and in particular measurements of beryllium isotopes...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a planned next-generation ground-based water Cherenkov detector array designed for high-energy gamma-ray astronomy. SWGO will consist of a dense, tightly packed inner array surrounded by a sparse outer array. The technology choices for the inner array have been narrowed into a baseline design, which consists of optically isolated steel...
KM3NeT is a multi-purpose neutrino detector under construction in the Mediterranean Sea and currently taking data with a partial detector configuration. It is composed of a network of two deep-sea water-Cherenkov detectors located at two different sites: ARCA (Italy), optimised for the detection of high-energy cosmic neutrinos in the TeV-PeV range, and ORCA (France), optimised for low-energy...
The origin, acceleration, and propagation mechanisms of cosmic rays are fundamental scientific issues in the field of international cosmic ray research. The composition and energy spectrum of cosmic rays contain rich information about physical processes. Therefore, accurately measuring the composition and energy spectrum of cosmic rays is a key approach to studying and validating cosmic ray...
Cosmic ray background reaching Earth is a deeply interesting field of research. A precise measurement of the rate of secondary cosmic rays arriving at the Earth surface provides us ample information about the solar activity, the space weather and the possible forecasting of magnetic storms. With all of these purposes in mind a new generation of small, versatile and affordable tracking...
Cherenkov Telescope Array Observatory (CTAO) represents the next-generation facility for gamma-ray astronomy. It will be the largest gamma-ray observatory ever built, with sites in both the Northern and Southern Hemispheres. CTAO will provide extensive energy coverage from 20 GeV to 300 TeV, allowing us to advance our understanding of the universe significantly.
CTAO will issue scientific...
Since its launch, in December 2015, the space-based DArk Matter Particle Explorer (DAMPE) has been operating smoothly, continuously collecting data for more than nine and a half years. The Silicon-Tungsten tracKer-converter (STK) of DAMPE is designed to measure the absolute value of the charge and precisely reconstruct the trajectory of the incident charged particle. The STK consists of six...
POEMMA Balloon with Radio (PBR) is a NASA super pressure balloon mission building toward the proposed Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) dual satellite mission. In its planned 2027 launch, PBR will study Ultra-High-Energy Cosmic Rays, Neutrinos, and High-Altitude Horizontal Airshowers from 33 km above the Earth. By operating at balloon altitudes, PBR will provide a novel...
The Cherenkov Telescope Array Observatory (CTAO) is the next-generation gamma-ray observatory. CTAO foresees two observation sites, one located in the Northern Hemisphere (Canary Island of La Palma) and the other in the Southern Hemisphere (Atacama Desert in Chile), for observing gamma-ray events coming from all over the celestial vault.
Thanks to the CTA+ program, two Large-Sized...
Muon telescopes, distributed worldwide, serve as ground-based particle detectors that are simple, cost-effective, and highly robust. They typically consist of planes made from plastic scintillators or resistive plate chambers. Positioned on the Earth's surface, these detectors are mainly sensitive to secondary muons, which originate from the interactions of primary cosmic rays with the upper...
Recent studies have demonstrated the feasibility of Earth tomography using high-energy atmospheric neutrinos. High-precision geophysical models are essential to unravel Earth’s evolutionary history. The prevailing Preliminary Reference Earth Model (PREM) was established using traditional geophysical methods to determine the matter distribution throughout the Earth. The model however carries...
The Trans-Iron Galactic Element Recorder for the International Space Station (TIGERISS) is being constructed and is planned to be launched in 2027 and attached at the SOX location on the Columbus module on the ISS. TIGERISS will make the first definitive measurements of Ultra-Heavy Galactic Cosmic Rays (UHGCRs; Z >29) on an individual element basis past barium (56Ba), through the lanthinides,...
The Terzina telescope is designed to detect ultra-high energy cosmic rays (UHECRs) and Earth-skimming neutrinos from a 550 km low-Earth orbit (LEO) by observing Cherenkov light emitted by Extensive Air Showers (EAS) in the Earth’s atmosphere pointing towards the telescope and in the field of view. In this contribution, a simulation chain for the Terzina telescope onboard the NUSES mission will...
The LACT project will deploy 32 atmospheric Cherenkov telescopes with a diameter of 6 meters at Haizishan, Daocheng County, Sichuan Province, to conduct detailed structural measurements of over a dozen ultra-high-energy gamma-ray sources discovered by LHAASO. The cameras of the telescopes will use Silicon Photomultipliers (SiPM) as light sensors. We have collected samples provided by multiple...
SPaRKLE (Small Particle Recognition Kit for Low Energies) is a compact detector designed for $\gamma$-ray and low-energy charged particle physics in Low Earth Orbit. The project is carried out by an interdisciplinary team of students from the University of Trento and has been selected for the ESA Academy Experiments Programme 2023--2024. SPaRKLE is currently in Phase~C (Detailed Definition)....
The Large Array of Imaging Atmospheric Cherenkov Telescopes (LACT), comprising 32 telescopes, is currently under construction at the LHAASO site. The array will cover an area of nearly 1 km² and provide a unique platform for measuring the lateral distribution of Cherenkov light from extensive air showers. This paper systematically investigates the characteristics of this lateral distribution...
Following the Trinity Demonstrator, Trinity One will be the first of the 18 Cherenkov telescopes that make up the Trinity PeV-Neutrino Observatory. Located on Frisco Peak in Utah, Trinity One has the capability to observe 64% of the sky, allowing it to detect potential neutrino point sources with unprecedented sensitivity, ranging from 1 PeV to 10 EeV. We outline the design of Trinity One,...
Isolated active galactic nuclei (AGNs) serve as unique laboratories for studying nuclear activity driven solely by internal processes within galaxies. In this study, we analyze the X-ray emission of 2MIG isolated AGNs at redshifts up to 0.05. These AGNs are generally weak X-ray sources. Our sample consists of 61 isolated galaxies, with X-ray emission detected in only 25 of them. Among these,...
The rise of direct detection of gravitational waves (GWs) started a new era in multi-messenger astrophysics. Like GWs, many other astrophysical transient sources suffer from poor localization, which can span tens to thousands of square degrees in the sky. Moreover, as the detection horizon for these transients widens and the detection rate increases, current electromagnetic follow-up...
New planned and in-development experiments for direct cosmic ray detection in balloons or satellites use plastic scintillators readout by silicon photomultipliers (SiPMs) to provide timing information with resolutions in the order of picoseconds (ps). This information is essential for triggering, vetoing, or particle identification. Due to the particularly harsh environmental conditions these...
The number of very high energy transient sources is limited and the sample composition may be biased. With high duty cycle, wide field of view and high sensitivity, LHAASO is a promising facility to detect very-high-energy transient extra-galactic sources unbiasedly. For this purpose, we conducted an blind searching of transient phenomenon with time scale ranging from seconds to one month...
The Southern Wide-field Gamma-ray Observatory (SWGO) is proposed as a next-generation ground-based water Cherenkov detector array designed to study Very to Ultra-High-Energy gamma rays. It will be located in the Atacama Astronomical Park in Chile, at 4770 m above sea level, with a direct view of the Galactic Center and ample coverage of the Southern Sky. The proposed SWGO array will consist of...
The first detection of Gravitational Waves in 2015 marked the dawn of Gravitational Wave Astronomy, a new observational window to the Cosmos (Nobel Prize Physics 2017). Since then, the worldwide LIGO-Virgo-KAGRA (LVK) network of gravitational wave detectors have measured well over a hundred gravitational wave signals. To make students share in the thrill of discovery in an authentic setting...
Over the last decade, the scenario of choked jets embedded in core-collapse supernovae (CCSNe) has garnered significant attention. The extended stellar envelopes of red supergiant (RSG) and blue supergiant (BSG) stars, both progenitors of Type II supernovae, pose a challenge to the launch of a powerful jet capable of piercing through them. As the jet propagates, it dissipates energy in a...
Photons of cosmic origin with maximum energies in the PeV ($10^{15}\,\text{eV}$) range have been discovered by several gamma-ray observatories. Photons at such energies are potentially produced during the acceleration of charged leptons and hadrons in so-called PeVatrons. The charged hadrons escaping from galactic PeVatrons are widely assumed to contribute significantly to the galactic...
The cosmic ray neutron monitor detects secondary cosmic ray neutrons with energies ranging from ~ 500MeV to several GeV. This energy range is associated with solar activity. Therefore, it is useful for studying the Sun and the space environment. We operate two neutron monitors: one in Daejeon on the Korean Peninsula and the other at Jang-Bogo research station in Antarctica. Recently, we...
RS Ophiuchi is a recurrent nova which explodes on average every 10 or 20 years. These explosions result in nova shocks from which non-thermal particles and radiation are produced. The most recent outburst of RS Ophiuchi in 2021 has been observed by a few different gamma-ray instruments including Fermi-LAT, HESS and MAGIC. Interestingly, TeV gamma rays are only detected about two days after the...
The Pacific Ocean Neutrino Experiment (P-ONE) is set to deploy its first detection string in the Cascadia Basin off the coast of British Columbia, Canada. As a next-generation Cherenkov neutrino telescope, P-ONE will be sensitive to ultra-high-energy neutrinos (10³–10⁸ GeV) from astrophysical sources. To effectively capture these rare physics signatures, the experiment's trigger system must...
Our research investigates the cascade properties of fast-mode magnetohydrodynamic (MHD) turbulence in compressible plasmas, which play a crucial role in cosmic ray scattering and acceleration. Fast modes are known to scatter cosmic rays much more efficiently than Alfvén modes, yet the dynamics behind their energy transfer remain under-explored. To address this gap, we conduct high-resolution,...
In this study, we investigate the potential to observe, for the first time, Hawking radiation from asteroid-mass black hole morsels, hypothesized to form during catastrophic astrophysical events such as binary black hole mergers. The black hole morsels, ejected during the merger, may account for the unobserved merger mass and are predicted to emit a characteristic gamma-ray signal spanning the...
Characterizing the astrophysical neutrino flux with the IceCube Neutrino Observatory traditionally relies on a binned forward-folding likelihood approach. Insufficient Monte Carlo (MC) statistics in each bin limits the granularity and dimensionality of the binning scheme.
A neural network can be employed to optimize a summary statistic that serves as the input for data analysis, yielding the...
The transport of Solar Energetic Particles (SEPs) through the interplanetary space remains a challenging aspect in space physics. The effects of the interplanetary magnetic field and solar wind turbulence on the SEP arrival to Earth has motivated the adoption of physics-based approaches in operational space weather forecasting. 3D physics-based models offer a framework for incorporating the...
Virgo, hosted at the European Gravitational Observatory (EGO) in Cascina, Italy, is one of the most advanced physics research centers in Europe. As part of its education and public outreach mission, Virgo virtually opens its doors for schools across Europe and beyond with remote guided tours in English. Visiting a cutting-edge research laboratory like Virgo offers a unique opportunity to...
The LHAASO-KM2A can precisely measure the shower sizes of both electromagnetic particles and muon content in cosmic-ray air showers. In this study, we present a method for estimating the energy of primary cosmic rays over a broad zenith angle range (0°–40°) with a consistent zenith-angle correction. This wide range zenith angle enhances cosmic-ray measurement statistics by significantly...
