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...
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...
The last decade has opened up the universe of high-energy astrophysical neutrinos to observation, and there is now a body of publicly available data which will continue to grow from experiments such as IceCube and KM3NeT. Among other things, this allows us to test models of beyond-Standard Model neutrino physics. However, such analyses require code that includes statistical methodology and...
The identification of $\gamma$-rays from the predominant hadronic-background is a key aspect in their ground-based detection using Imaging Atmospheric Cherenkov Telescopes (IACTs). Current methods rely on Boosted Decision Trees (BDTs) or goodness-of-fit parameters, which are limited in their ability to exploit deep correlations in complex data. Deep learning (DL)-based methods are able to...
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...
Both Rubin Observatory and CTAO will be collecting data by 2026, marking a new era in optical and gamma-ray astronomy. Compared to predecessors like ZTF, H.E.S.S., MAGIC, and VERITAS, their enhanced sensitivity will extend extragalactic observations to at least redshift of ∼2.5. This advancement offers fresh insights into non-thermal astrophysical sources, particularly blazars - radio-loud AGN...
We propose novel numerical schemes based on the Boris method in curved spacetime, incorporating both hadronic and radiative interactions for the first time. Once the proton has lost significant energy due to radiative and hadronic losses, and its gyroradius has decreased below typical scales on which the electromagnetic field varies, we apply a guiding center approximation (GCA). We...
A novel hybrid positioning system has been developed from the ground up for the Baikal-GVD neutrino telescope. It combines two independently operated subsystems: an inertial system and a hydroacoustic network. The hydroacoustic network employs acoustic modems installed at specific positions along the height of the detector strings, including some at the string anchors, while the inertial...
The Southern Wide-field Gamma-ray Observatory (SWGO) will be the first major wide-field instrument operating in the sub-TeV to PeV gamma-ray domain in the Southern Hemisphere. The primary site for SWGO is ‘Pampa La Bola’ at 4.8 km above sea level within the Atacama Astronomical Park in Chile. The observatory will be implemented as an array of water Cherenkov detectors: tanks containing pure...
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...
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...
Dark matter and neutrino detection experiments require the digitization of analog signals generated by PMTs or SiPMs. Since the output pulse widths of PMTs and SiPMs are relatively narrow, around tens of nanoseconds, high-quality, high-precision waveform acquisition necessitates a high-speed, high-precision analog-to-digital converter. For example, the Jiangmen Underground Neutrino Observatory...
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...
The Laser Interferometer Space Antenna (LISA) is a forthcoming space-based gravitational wave (GW) observatory designed to detect low-frequency GWs (0.1 mHz - 1 Hz) using a triangular constellation of three spacecraft separated by ~2.5 million km. As the first space-based interferometer for GWs, LISA will provide groundbreaking observations of massive black hole mergers, extreme mass-ratio...
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...
While remarkable progress has been made to understand the propagation of cosmic rays, a variety of astrophysical uncertainties persists. At energies below about 20 GeV, the cosmic-ray flux is significantly modulated by solar activity, a process that is not precisely understood. Using the recently published AMS-02 data for the time-dependent cosmic-ray fluxes, we study the effects of solar...
The IceCube Neutrino Observatory is a cubic-kilometer detector located in the Antarctic ice at the geographic South Pole. It reads out over 5,000 photomultiplier tubes (PMTs) to detect Cherenkov light produced by secondary particles, enabling IceCube to identify both atmospheric and astrophysical neutrinos. One of the main challenges in this effort is effectively distinguishing between muons...
The Cherenkov Telescope Array Observatory (CTAO) is an international observatory currently under construction, which will consist of two sites (one in the Northern Hemisphere and one in the Southern Hemisphere). It will eventually be the largest and most sensitive ground-based gamma-ray observatory. In the meantime, a small subarray composed of four Large-Sized Telescopes (LSTs) at the...
The KM3NeT Collaboration is constructing and managing two deep-sea neutrino telescopes on the Mediterranean Sea floor. These telescopes are composed of networks of light detectors enclosed in pressure-resistant glass spheres, known as digital optical modules. Each module contains 31 photomultipliers, each with a 3-inch diameter, along with acquisition electronics. The detection units consist...
The ASTRI Mini-Array is an INAF project aimed at constructing an array of nine imaging air Cherenkov telescopes (IACTs) for the very-high energy (VHE) gamma-ray detection at the Teide Observatory site (Tenerife, Canary Islands), finalised to observe astronomical objects emitting photons in the multi-TeV spectral band. Detailed simulations of atmospheric showers of Cherenkov events using...
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...
Software code generation using Large Language Models (LLMs) is one the most successful application of the modern artificial intelligence. Foundational models are very efficient when applied to popular frameworks and libraries, which benefit from documentation, code examples, and strong community support. However, many specialized scientific libraries lack these resources and often have...
Extragalactic very high-energy (VHE; $E>100\,$GeV) gamma rays suffer absorption in interactions with photons of the Extragalactic Background Light (EBL). The EBL is an isotropic diffuse field spanning the optical and infrared regions of the electromagnetic spectrum. Observational data allow for uncertainties in the current EBL models, which in turn affect VHE analyses. We present an...
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...
The HUNT (High-Energy Underwater Neutrino Telescope) is a next-generation neutrino telescope project. Each string in HUNT has dozens of optical modules (OM), which house a 20-inch photomultiplier tubes (PMT) within 23-inch glass spheres. These strings extend up to approximately 1 kilometer in length. To precisely measure the real-time attitude and location of each OM, we employ 9-axis IMU...
The IceCube Neutrino Observatory has measured an isotropic astrophysical neutrino flux through various detection channels for over 12 years. IceCube has also detected neutrino emission from the Galactic plane at the 4.5σ significance level compared to a background-only hypothesis, testing three models of Galactic diffuse emission: Fermi-LAT π0, KRAɣ5, KRAɣ50. We present an analysis combining 3...
Galactic diffuse emission (GDE) is a major component of the GeV gamma-ray sky. The Fermi bubbles and the Galactic center excess are two distinct diffuse components that garnered significant attention. The DArk Matter Particle Explorer (DAMPE) is a space-borne high-energy particle telescope aiming at measuring cosmic rays and photons in a broad energy range. These two sources are suitable for...
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 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...
Astrophysical neutrinos provide crucial insights into their sources and play a key role in multi-messenger astronomy. The neutrino flavor composition at Earth allows us to probe the mechanisms of neutrino production and cosmic ray acceleration, as well as the properties of the environments in which they originate. Understanding the flavor composition also offers a unique opportunity to test...
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 blazar TXS 0506+056 was the first astrophysical source to be associated with high-energy neutrinos, both temporally and spatially. This breakthrough followed the detection of a high-energy neutrino coincident with the blazar’s 2017 X-ray and gamma-ray flare. Additionally, IceCube has identified TXS 0506+056 as the second most prominent hotspot in the neutrino sky over 9.5 years of...
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...
The Radio Neutrino Observatory in Greenland (RNO-G) aims to detect UHE
neutrinos (E > 100 PeV). With an array of upward-facing near-surface antennas operating in the 80-700 MHz range, the RNO-G surface component is sensitive to broadband signals originating from many sources, such as background noise induced by the Milky Way. In this contribution, I use the measured Galactic noise to...
The ASTRI project, led by the Italian National Institute for Astrophysics (INAF), aims to deploy an array of nine small-sized (4-m diameter) Imaging Atmospheric Cherenkov Telescopes at the Teide Observatory in Tenerife. The system will study astronomical sources emitting in the very high-energy range above 1 TeV up to 200 TeV. Each telescope is equipped with a Cherenkov camera based upon...
The Radio Neutrino Observatory in Greenland (RNO-G) aims to detect ultra-high-energy astrophysical neutrinos (E > 100 PeV). These neutrinos interact with the Greenlandic ice sheet, generating a particle cascade that emits radiation in the radio frequency range through the Askaryan effect. Once fully deployed, RNO-G will be the largest in-ice radio neutrino detector. Currently, 8 out of 35...
Accurate calibration is essential for maximizing the scientific output of the Cherenkov Telescope Array Observatory (CTAO). The Calibration Pipeline, a core component of the Data Processing and Preservation System (DPPS), is part of the low-level offline reconstruction software. It is responsible for generating and maintaining high-precision calibration products. It encompasses the refinement...
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...
Recently, the IceCube Neutrino Observatory has reported a deviation from the single power law in the extragalactic diffuse neutrino flux, primarily driven by the hardening of the low-energy flux below 30 TeV, but ultimately, causally uncertain. The spectrum above 1 PeV also remains uncertain; it could continue as a single power law, cut off, or exhibit other features. A neural network-based...
The IceCube Neutrino Observatory, located at the geographic South Pole, uses the glacial ice volume to detect astrophysical neutrinos. Detection of the neutrinos from the northern sky provides the opportunity to use a large effective volume. However, as the cross-section increases with energy, most high-energy neutrinos are absorbed by the Earth. On the other hand, probing down-going PeV...
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...
In 2023 the IceCube collaboration published the first observation of the Galactic diffuse neutrino flux. This emission is produced by cosmic rays interacting with the interstellar medium. The measurement of this flux can help to understand the distribution of cosmic rays in the Galaxy.
In this poster, we present plans for a new analysis combining different event topologies. IceCube measures...
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 knee-like structure of cosmic rays spectrum still need to be understood. The Klein-Nishina effect of the inverse Compton scattering results in lower efficiency for energy loss of electrons, which gives the probability for proton dominate PeV. Based on the fact that lots of very-high-energy and ultra-high-energy sources are associated with pulsar wind nebula, we consider the contribution...
The origin of high-energy astrophysical neutrinos remains unknown despite growing statistics. Direct source association and stacking analyses of existing data have so far only been able to account for a small fraction of the astrophysical neutrino flux. In this work we present the results of a new approach to this problem that makes use of the angular, harmonic cross-correlation between...
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 Jiangmen Underground Neutrino Observatory (JUNO), located in southern China, is a next-generation neutrino experiment equipped with a 20-kton liquid scintillator detector. JUNO's primary goal is to determine the neutrino mass ordering (NMO) through reactor neutrino oscillation measurements. Construction of JUNO is nearing completion, with water filling finished and liquid scintillator...
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...
The cosmic neutrino background is a prediction of standard cosmology but remains undetected due to the extremely low energies involved. By elastic scattering on cosmic-ray nuclei, these relic neutrinos can be upscattered to ultra-high energies observable by current neutrino telescopes such as the IceCube Neutrino Observatory and the Pierre Auger Observatory. Earlier calculations only took into...
The huge luminosity, the redshift distribution extending up to z > 9 and the association with the explosive death of very massive stars make long Gamma-Ray Bursts (GRB) extremely powerful probes for the exploration of the early Universe (star formation rate evolution up to the first generation of stars, cosmic reionization, luminosity function and metallicity evolution of primordial...
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...
The Cherenkov Telescope Array Observatory (CTAO), currently under construction, will mark the beginning of a new era of high-precision very high-energy gamma-ray astrophysics. As operations progress, the accuracy of scientific measurements will increasingly be limited by systematic uncertainties. To address this challenge, CTAO has set ambitious performance goals for energy and angular...
The Cherenkov Telescope Array Observatory (CTAO) will be the world’s leading facility for very-high-energy gamma-ray astrophysics, producing unprecedented volumes of raw and processed data. Efficient processing, storage, and long-term preservation of these data are critical for ensuring scientific reproducibility and accessibility. The Data Processing and Preservation System (DPPS) is designed...
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...
We present the results of a novel deep learning network applied to data from the HAWC Observatory to improve the reconstruction of high-energy gamma-ray events. HAWC consists of 300 large water Cherenkov detectors, each of which is instrumented with 4 photomultiplier tubes (PMTs) which collects the Cherenkov light produced by the extensive air showers initiated by cosmic rays or high energy...
The Cherenkov Telescope Array Observatory (CTAO), a next-generation ground-based gamma-ray observatory, will be composed of two arrays of multiple imaging atmospheric Cherenkov telescopes (IACTs) located in both the Northern and Southern Hemispheres. Its goal is to enhance the sensitivity of current instruments by a factor of five to ten over an energy range from 20 GeV to over 300 TeV. IACT...
The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based observatory for very-high-energy (VHE) gamma-ray astronomy. The Large-Sized Telescope prototype, LST-1, located on the Canary Island of La Palma, is responsible for observation of the low-energy range of the VHE gamma-ray spectrum. It is undergoing commissioning and has already observed the Crab Nebula as a...
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...
The Array Data Handler (ADH) of the Cherenkov Telescope Array Observatory (CTAO) is a central component of the software operations for the telescopes arrays. It handles trigger events and raw data from all telescopes, as well as data from environmental and array calibration instruments. Following the initial release of the ADH, which is now capable of handling data from a single telescope,...
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...
Ultrahigh-energy cosmic rays (UHECR) should produce ultrahigh-energy neutrinos (UHEN) as byproducts of their propagation. Many candidate UHECR source models also predict an emission of UHEN local to their acceleration sites. The Payload for Ultrahigh Energy Observations (PUEO) is a balloon-borne observatory that scans the Antarctic ice for these UHEN through their Askaryan emission and is the...
Very large neutrino telescopes offer unique opportunities in detecting neutrinos from the next core-collapse supernova (CCSN), following the first and only detection in 1987. The TRopIcal DEep-sea Neutrino Telescope (TRIDENT) is a next-gen neutrino telescope to be built in the South China Sea. Although primarily designed for high energy neutrino detection, a nearby CCSN could register a high...
The TAIGA astrophysical complex [1], located in the Tunka Valley, 50 km from Lake Baikal, was created for research in the field of ultra-high-energy gamma-ray astronomy and cosmic ray physics. This report provides a detailed description of the methodology for detecting gamma rays using the installation TAIGA-IACT atmospheric Cherenkov telescopes in stereo mode [2] and presents the results...
We report results of a new search using a 15-year long (up to August, 4 2023) data set at energies higher than 4 GeV for SNRs in the Large Magellanic Cloud applying two clustering methods: the Minimum Spanning Tree (MST), and the combination of Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and DENsity-based CLUstEring (DENCLUE).
We found positive indications for 8 new...
: The nearby active galaxy IC 310, located on the outskirts of the Perseus galaxy cluster, is a bright and variable multi-wavelength emitter, ranging from the radio regime to very high-energy gamma rays above 100 GeV. Using the LHAASO-WCDA real-time alert system, a TeV gamma-ray flare from IC 310 was detected and reported (ATel #16513), with subsequent activity observed in ATel #16540. In this...
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...
AMEGO-X is planned as a satellite to explore all-sky medium energy gamma-ray observation. MeV gamma-ray observation is important for multi-messenger astronomy. AMEGO-X detector is based on the Si-stacked Compton camera and currently developped AstroPix is considered as Si sensors.
AstroPix is a novel high-voltage CMOS active pixel sensor. AstroPix has to be 0.5 mm thick and active full...
FlashCam is a high-performance camera design for ground-based, imaging atmospheric Cherenkov telescopes. An advanced prototype has been successfully operating in the CT5 telescope of the H.E.S.S. experiment since December 2019.
The FlashCam collaboration is currently preparing a second improved FlashCam camera, which is a candidate for the MST pathfinder telescope located at the Southern CTAO...
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 P-ONE (Pacific Ocean Neutrino Experiment) is a future cubic km size, water Cherenkov neutrino telescope that will be located in the Pacific Ocean off the coast of Canada. This telescope will contribute to the search for astrophysical neutrinos sources, test improved detection and calibration techniques, and conduct valuable oceanographic measurements.
The first line of the detector,...
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 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 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...
Inspired by the detection of KM3NeT-230213A, the most energetic neutrino ever observed, we present a statistical analysis of the diffuse neutrino flux at the highest energies.To enhance the estimation of the muon background, we refine the modeling of atmospheric backgrounds and extend the capabilities of the MUPAGE generator with modifications optimized for ultra-high-energy...
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...
The recent result from IceCube detecting the Milky Way (MW) in neutrinos is the first step towards including these particles in multi-messenger studies of our Galaxy.
The origin of the MW's cosmic rays (CRs) and their maximum energies can be constrained from the observed Galactic neutrino flux by comparing the measurements to the modelled spectra from CR propagation codes.
Using the latest...
The Large High Altitude Air Shower Observatory (LHAASO) has discovered over 40 ultra-high-energy gamma-ray sources with energies exceeding 100 TeV, ushering in a new era for ultra-high-energy gamma-ray astronomy. To better understand the fine structure of gamma-ray emissions from these sources, the team proposed the Large Array of imaging atmospheric Cherenkov Telescopes (LACT) experiment,...
The Askaryan Radio Array (ARA) is an ultra-high energy (UHE, >10 PeV) neutrino detector at the South Pole, designed to observe radio Askaryan emission from neutrino interactions in ice. A key challenge in reconstructing neutrino arrival directions in ARA is accurately determining the polarization of detected signals, as polarization provides crucial information about the emission geometry of...
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...
The TRopIcal DEep-sea Neutrino Telescope (TRIDENT) is a next-generation neutrino telescope to be built in the South China Sea. We are designing a sea trial platform for TRIDENT aiming to measure in-situ seawater properties, including radioactivity, bioluminescence, the opical absorption and scattering lengths , and the atmospheric muon flux. Compared to the version completed in September 2021,...
The IceCube Neutrino Observatory is set to deploy the IceCube Upgrade during the Austral summer of 2025–2026. The Upgrade consists of seven new strings positioned near the center of the existing IceCube detector. These strings feature three types of newly-designed optical modules. Notably, the new modules generate substantially higher data rates, necessitating in-module data processing and...
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...
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...
We develop Artificial Intelligence agents based on instruction-finetuned large language models (LLMs) to assist in the engineering and operation of the Cherenkov Telescope Array Observatory (CTAO) Control and Data Acquisition Software (ACADA). These agents align with project-specific documentation and codebases, understand contextual information, interact with external interfaces, and...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a future TeV gamma-ray observatory to be built in Chile. The high-duty cycle experiment will consist of over 6000 water-Cherenkov tanks equipped with two photomultiplier tubes each. The available computational infrastructure will not be sufficient to handle all the raw data SWGO will produce. Therefore, to limit the computational...
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 Southern Wide-field Gamma-ray Observatory (SWGO) is a proposed next-generation TeV gamma-ray observatory and the first wide-field experiment dedicated to exploring the southern gamma-ray sky. In this study, we present DeepEASTER (Deep learning for Extensive Air Shower Targeted Event Reconstruction), an attention-based neural network designed to optimize event reconstruction for SWGO. The...
Neutrino Oscillation Tomography probes the structure of the Earth by leveraging the dependence of atmospheric neutrino oscillation probabilities on changes in the electron number density (the product of density and composition) along the neutrino path. This technique provides a complement to other geophysical methods (e.g., seismology) for studying the Earth's core and mantle.
A target for...
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...
Pulsars, magnetars, and black holes, being high-energy astrophysical objects, function as natural experimental settings to explore high-energy radiation. Presenting a comparative analysis of their dominant emission processes, focusing on curvature radiation, synchrotron radiation, inverse Compton scattering, and magnetic reconnection effects, the paper also investigates high-energy radiation...
The KASCADE Cosmic-Ray Data Centre (KCDC) is a public data centre for high-energy astroparticle physics, built on the legacy data of the KASCADE experiment. For over a decade, KCDC has supported major research data practices, such as open data, open source, and open education. It provides users with a public REST (REpresentational State Transfer) API for data retrieval, information on data...
Fast Blue Optical Transients (FBOTs) are luminous short-lived events, that strongly emit at blue colors around their peak in the optical waveband. The late-time emission shows similarities to supernovae (SNe) associated with long GRBs and superluminous SNe but the origin of FBOTs is not yet understood. However, the fast rise-time of the optical emission of a few days indicates fast-moving...
Gravitational-Wave detections employ the Matched Filtering based algorithms for making the detections. Matched Filtering works by matching data from the incoming data stream with waveform templates from the templates banks generated in some interested parameter space. Since the parameter space can be large if we want to include most of the detections, generating a template bank can involve...
Understanding solar flare events is fundamentally important for space-weather predictions and in-orbit assets. Solar flares emit sub-atomic particles and photons across a wide range of energies, affording us a number of messengers to understand the inner workings of these energetic events.
In this paper, we present our work on using Fermi-LAT observations to study solar flare events over...
The Einstein Telescope (ET) is a third-generation gravitational wave observatory. As a ground-based detector, it is particularly susceptible to seismic noise at low frequencies, particularly for frequencies below 10 Hz. Accurately predicting seismic waveforms can aid in mitigating the impact of seismic noise, thereby enhancing the detector's sensitivity in these frequency ranges—an essential...
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...
In standard cosmological models, dark matter (DM) overdensities known as prompt cusps can form in the early Universe, persisting through cosmic time. Unlike resolved DM substructures, these dense cusps produce an annihilation flux that scales linearly with the DM density, $\rho$, rather than $\rho^2$. This results in an extended, yet bright, annihilation signal from massive structures such as...
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...
This contribution introduces gammapy_SyLC, an open-source Python package designed for time-domain analysis of gamma-ray light curves, with applications to AGNs. SyLC enables synthetic light curve generation with controlled variability properties using the Timmer&Koenig and Emmanoulopoulos algorithms. It also implements statistical tools for characterizing time series properties through power...
The High-Energy Underwater Neutrino Telescope (HUNT), designed for deployment at depths exceeding one kilometer, will host a detector array covering an instrumented volume of approximately 30 cubic kilometers. It aims to explore the neutrino sky from TeV to 100 PeV. Traditional CPU-based simulations using Geant4 faces a major bottleneck, as optical processes dominate the computational load. To...
In the last decade, IceCube has been able to probe astrophysical sources to test cosmic ray acceleration mechanisms and shine light on properties previously unseen, such as sub- photospheric density and baryon loading. While IceCube is specifically built for neutrino astronomy at TeV and higher neutrino energies, GeV neutrino detection is possible by utilizing the densely populated subvolume...
The Compton Spectrometer and Imager (COSI) is an upcoming NASA Small Explorer mission focused on exploring the 0.2-5 MeV energy range in the electromagnetic spectrum. This MeV gap has long been underexplored due to technical challenges, in particular the high instrument and astrophysical backgrounds in this energy regime. COSI aims to conduct spectroscopy, imaging, and polarimetry of cosmic...
GRANDlib is an open-source software tool designed to meet the computational challenges of the Giant Radio Array for Neutrino Detection (GRAND), such as production of numerous simulations of particle showers and their detection, and a high data throughput. Its primary goal is to perform end-to-end simulations of the detector operation, from the interaction of ultra-high-energy particles,...
ALPAQUITA is the prototype of a new gamma-ray observatory, the Andes Large Particle Detector for Cosmic Ray Physics and Astronomy (ALPACA), currently under construction at an altitude of 4,740 meters above sea level on a wide plateau near Chacaltaya Mountain in Bolivia. ALPACA will be a hybrid detector comprising a large area of scintillator-based detectors and underground water Cherenkov muon...
Ultra-high-energy photons have long been sought as tracers of the most energetic processes in the universe. Several components contribute to an expected diffuse photon flux, including interactions of cosmic rays with Galactic matter and radiation fields, as well as more exotic scenarios such as the decay of super-heavy dark matter. Regardless of their origin, the expected flux is extremely...
The very-high-energy γ-ray source HESS J1809-193 has been detected by the LHAASO and HAWC observatory beyond 100 TeV energy. It is an interesting candidate for exploring the underlying mechanisms of γ-ray production due to the presence of supernova remnants, pulsars, and molecular clouds close to it. We have considered the injection of the energetic cosmic rays from a past explosion, whose...
Numerous high-energy gamma-ray sources have been detected along the Galactic Plane. While some of them are associated to objects like supernova remnants or pulsar wind nebulae, a significant portion remains unassociated, hindering our understanding of the objects and detailed mechanisms that produce such extreme energies. To pinpoint the origins of the gamma-ray emission, we need to identify...
The detection of Tera-electronvolt (TeV; 10$^{12}$ electronvolts) emission in extragalactic galaxies has sparked renewed interest in exploring the characteristics and underlying physics of the enigmatic emission component. To delve deeper into the nature of TeV-detected blazars and unravel the mechanisms driving their high-energy behavior, we compiled a comprehensive sample comprising 51 TeV...
The Large-Sized Telescope 1 (LST-1) is a 23-meter atmospheric imaging Cherenkov telescope designed to achieve gamma-ray sensitivity down to energies of tens of GeVs. The first prototype has been constructed and is currently undergoing commissioning at the northern site of the Cherenkov Telescope Array Observatory (CTAO) at La Palma, Spain. Three additional LSTs are currently under construction...
The location of gamma-ray-emitting region in blazars has been an open issue for several decades and is still being debated. We use a large sample of gamma-ray-loud FSRQs with available spectral energy distributions and employ a so-called “seed photon factor approach” to locate the γ-ray production region. We principally ascertain that the GeV emission originated far beyond the broad-line...
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...
In the last decade, Graphic Processing Units (GPUs) have become a standard component of High Performance Computing systems and are now ubiquitous in consumer-grade hardware. Their massive parallel architecture offers significantly higher computing throughput and energy efficiency than traditional CPU-based solutions. In the context of Imaging Atmospheric Cherenkov Telescopes (IACTs),...
Ultra-High-Energy neutrinos are an invaluable messenger for learning about the most energetic and distant processes in the universe. Detecting them is challenging due to their extremely low flux and small cross section, necessitating immense detection volumes. The Radio Neutrino Observatory in Greenland (RNO-G) addresses this challenge by leveraging the Askaryan effect, using sparse radio...
The IceCube Upgrade, currently under construction at the geographic South Pole, is the next development stage of the IceCube detector. It will consist of seven new columns of novel optical sensors and advanced calibration devices densely deployed at the bottom center of the existing array. The sensors are frozen into the ice in boreholes created by hot water drilling. The refreezing forms hole...
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...
In 2016, the IceCube Neutrino Observatory launched its realtime program. When a neutrino candidate of likely astrophysical origin is detected, a public alert is issued, typically within one minute. These alerts allow the astrophysical community to follow up on the region of the sky where the neutrino likely originated. Initially, the system issued around six track-signature alerts per year,...
The High Altitude Water Cherenkov (HAWC) observatory surveys the very-high-energy sky in the energy range between 300 GeV and >100 TeV. Its wide field of view makes it particularly suitable for studying large, extended regions of emission that often contain multiple point and diffuse sources of gamma rays. Existing blind search methods to detect sources in HAWC data use a computationally...
The IceCube Upgrade is a planned extension to the IceCube Neutrino Observatory which will enhance the array's sensitivity with the addition of approximately 700 advanced sensors and calibration devices distributed across seven new "strings.””. Critical to this effort is the Upgrade in-ice communications infrastructure, which allows data transfer between the new modules and the surface data...
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...
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...
Gamma-ray observations of astrophysical neutrino sources are crucial for understanding neutrino production in extreme cosmic environments. The Cherenkov Telescope Array Observatory (CTAO), the first open-access ground-based gamma-ray observatory, is under construction in both hemispheres, CTAO-North in La Palma (Spain) and CTAO-South in the Atacama Desert (Chile). Covering an energy range from...
The study of high-energy neutrino emission from astrophysical sources is a key component of multi-messenger astronomy, aiming to uncover the mechanisms of cosmic particle acceleration. Astrophysical sources capable of accelerating cosmic rays to very high energies are expected to produce both neutrino and gamma-ray emissions. Consequently, potential neutrino emissions from known gamma-ray...
Pulsar wind nebulae are bubbles of magnetized electron-positron plasma formed by interaction between ultra-relativistic pulsar winds and environmental materials. Their emissions cover a wide range of wavelength, and especially their persistent gamma-ray emissions make it essential to model their properties accurately for a proper interpretation of the visible Galaxy. From previous...
This study investigates the damage threshold and recovery time of photomultiplier tubes (PMTs) with bialkali metal coatings, focusing on their quantum efficiency (QE) degradation under intense light exposure and thermal stress. To simulate prolonged sunlight exposure, PMTs were subjected to a xenon lamp for varying durations, with QE measured before and after exposure. Similarly, thermal...
TRopIcal DEep-sea Neutrino Telescope (TRIDENT) will use large-area silicon photomultiplier (SiPM) arrays in the hybrid Digital Optical Module (hDOM) to improve the single-photon time resolution of Cherenkov radiation detection, achieving better angular resolution.
We present the design of the SiPM array readout electronics.
The front-end circuit consists of SiPM arrays in a series-parallel...
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,...
A new approach has been proposed for formulating quantum field theory concerning neutrino oscillations. This method associates the charged-current vertices of a single second-order Feynman diagram with the emission and detection of neutrinos, while also incorporating their propagation between these points. A master formula has been developed for calculating the rate of charged lepton...
Recent advancements in single-photon detection, such as Single-Photon Avalanche Diodes (SPADs), have enabled picosecond-resolution measurements of photon arrival times. These technologies are crucial for applications like Satellite Laser Ranging (SLR) and Intensity Interferometry (II), where atmospheric effects on photon propagation remain a key limiting factor. Previous studies predicted...
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....
Neutrino observations are a crucial component of multi-messenger astronomy, but are currently limited by effective area and high atmospheric background. However, while other telescopes with limited field of view must be pointed in order to capture observations, IceCube’s full-sky field of view and high uptime make it an excellent instrument for realtime follow-up of astrophysical transient...
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...
ASTRI is an international project led by the Italian National Institute for Astrophysics (INAF) aimed at the construction and operation of an array of nine Imaging Atmospheric Cherenkov Telescopes (ASTRI Mini-Array) at the Observatorio del Teide in Tenerife. The primary goal of the project is to study gamma-ray astrophysical sources in the very high-energy domain, particularly at multi-TeV...
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...
Atmospheric neutrinos play a crucial role in a wide range of physics analyses at Super-Kamiokande. They serve as signals for testing the neutrino mass ordering, while also contributing as backgrounds in searches for rare events such as proton decay, supernova neutrinos, and cosmic dark matter interactions. Tagging neutrons in atmospheric neutrino interactions significantly enhances these...
The Super-Kamiokande detector has measured solar neutrinos for more than 25 years.The sensitivity to solar neutrino measurement is limited by the uncertainties of energy scale and the background modeling. One of the major background events is the spallation products created by the cosmic ray muons in the detector water tank. Some of the negative muons stop in the tank and are captured by the...
Gamma-Ray Bursts (GRBs) afterglows are rapidly decaying signals that pose significant detection challenges, requiring improved methods to track their temporal evolution. In this study, we systematically compare various techniques for detecting GRB-like transient emissions at very high energies (VHE, >100 GeV). Our analysis includes time-dependent extension of the standard method (i.e., Li & Ma...
The Askaryan Radio Array (ARA) is a neutrino observatory at the South Pole designed to search for ultra-high energy (UHE) neutrinos by observing radio emission from the Askaryan effect in Antarctic ice. Ice is a preferred detection medium for neutrino observatories because it is a radio-transparent, dense medium available in large volumes in nature, which is necessary for searching for the low...
A couple of classes of astrophysical objects such as young massive stellar clusters (YMSCs) have recently emerged as promising galactic PeVatron candidates, potentially explaining the knee of the cosmic-ray spectrum as alternative to isolated supernova remnants (SNRs). Meanwhile, the LHAASO observatory is the first to effectively probe the photon detection band above 0.1 PeV, that can...
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...
The search of γ-ray emission from accreting pulsars in X-ray binaries (XRBs) has been ongoing for some time. Recent marginal detections in high-mass X-ray binaries (HMXBs) have sparked renewed interest in this area. Anticipating future advances in γ-ray telescopes, we investigate the expected emission above 10 GeV from XRBs using an enhanced Cheng & Ruderman model. This model incorporates...
Neutrinos play an important role in multi-messenger astronomy, as they can probe dense environments and thus provide important insights into the properties of the sources. Multiple neutrino telescopes continuously observe the sky, across many decades of energies from MeV to PeV, and are often used for follow-up searches of transient phenomena detected by other messengers. MOMENTA is an...
We present the results of year-long monitoring of inherent optical properties of deep waters of lake Baikal in the wavelength range of 400–620 nm within the effective volume of the deep underwater neutrino telescope Baikal-GVD in 2024. The measurements were performed using a dedicated device, «BAIKAL-5D» №2, at a depth of 1180 m. Measurements of the absorption spectrum, scattering length at...
Blazars are a subclass of active galactic nuclei (AGN) characterized by relativistic jets oriented close to our line of sight, exhibiting extreme variability across multi-band observations. This study performed variability analysis of multi-band light curves for the blazar OJ 014 (J0811.4+0146) using data from Fermi-LAT, Swift-XRT/UVOT, and RATAN observations spanning from August 2008 to...
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...
In the coming years, the coordination and accessibility of telescopes and observatories across the globe will be essential towards the success of multi-messenger astrophysics researches. The ACME project, funded by the European Union, aims to facilitate and improve the access to multi-messenger data and services. It brings together about forty institutes across Europe, covering all domains in...
BL Lacertae is a well-known high-energy BL Lac object that has exhibited several epochs of very high energy (VHE) gamma-ray flaring events. On October 5, 2024 (MJD 60588), BL Lacertae underwent prominent flaring activity, which was detected by instruments covering a wide energy range from optical to TeV gamma rays. In this work, we aim to study the spectrum and variability of BL Lacertae based...
The Large Array of Imaging Atmospheric Cherenkov Telescopes (LACT) is an array of imaging atmospheric Cherenkov telescopes, while the Muon Detector (MD) of the square kilometer array (KM2A) measures the muon component of extensive air showers. Both are located at the LHAASO site. KM2A has demonstrated significant gamma/proton discrimination power, ranging from (10^2) to (10^5) at energies...
Currently, the identification of neutrino sources relies on joint observations with electromagnetic telescopes. This method has led to some successes, but is constrained by the field of view, availability, and observational limitations of traditional telescopes. The ongoing development of neutrino detectors around the world suggests that future datasets will allow for precise source analysis...
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,...
The flux of cosmic neutrinos is measured with unprecedented accuracy, and on an extended wide energy, by different experiments. In order to accurately interpreted this data, precise predictions of the production processes, specifically the cross section for the production of neutrinos from the interaction of cosmic-ray protons and helium with atoms of the interstellar medium, are necessary. In...
Pulsar wind nebulae (PWNe) are one of the most representative examples of galactic gamma-ray emitters and are thought to be the origin of cosmic ray (CR) positrons and knee CRs. The free energy of these non-thermal particles is the rotational energy of the central pulsar, but we have not understood how the rotational energy is converted into the pulsar wind, how the pulsar wind is dissipated,...
The first CTAO Large-sized (LST-1) and MAGIC telescopes are two Imaging Cherenkov telescope (IACT) systems located at the Roque de los Muchachos Observatory on La Palma, Canary Islands. Rapid availability of quality data products to both collaborations is crucial for physics alerts, scheduling, and data quality assurance. Additionally, the large size of the raw data makes its transmission to...
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...
nuSpaceSim is a highly-efficient (e.g. fast) module-based, end-to-end simulation package that models the physical processes of cosmic neutrino interactions in the Earth, the subsequent extensive air showers induced by the Earth-emergent leptons, the EAS optical Cherenkov and radio emission, signal attenuation, and the detector response to determine the sensitivity to both the diffuse cosmic...
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...
The KM3NeT observatory detected the most energetic neutrino candidate
ever observed, with an energy between 72 PeV and 2.6 EeV at the 90% confidence level. The observed neutrino event is likely of cosmic origin. This study investigates the possibility that the neutrino was produced within the Milky Way. Considering the low flux of the Galactic diffuse emission at these energies, the lack of a...
The Cherenkov Telescope Array Observatory (CTAO) is a next-generation gamma-ray observatory in both the Southern (Paranal, Chile) and Northern Hemisphere (La Palma, Spain) and will consist of up to 100 imaging atmospheric Cherenkov telescopes. With sensitivity far exceeding current facilities, CTAO will provide detailed measurements of gamma rays from GeV up to a few 100s of TeV. CTAO has a...
Currently, the Baikal-GVD neutrino telescope data processing system analyzes the acquired data in real time to search for neutrino signals from astrophysical sources. This includes following up on multimessenger alerts such as HE neutrino alerts from IceCube, gamma-ray flares and gravitational wave events. The GVD online analysis system classifies events into HE and LE ranks for both...
Among the different parts of its vast physics programme, DUNE will aim at observing neutrinos from a Core-Collapse SuperNova Burst (CCSNB). The experiment will then contribute to SNEWS, to provide both a trigger signal and a reconstructed direction for the explosion. Online pointing, achieved in a timescale of a few minutes, will allow to move telescopes in the correct direction to observe...
here are currently many Cherenkov neutrino telescopes being deployed and designed across the world. These detectors are exploring new optical sensors and geometric configurations to maximize their physics goals. Alongside detector R&D, machine learning (ML) has become established as a promising avenue for reconstructions in these detectors; however, there has not been a consistent comparison...
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...
High energy neutrino detectors are arrays of optical sensors distributed over large volumes of transparent media, such as water or ice, and sensitive to the Cherenkov radiation emitted by the charged products of the neutrino interactions.
Despite the same scientific objectives, various cosmic neutrino telescopes adopted different layout and technical solutions for their optical sensors,...
The NectarCAM is a camera designed for the Medium Sized Telescopes (MSTs) of the northern site of the Cherenkov Telescope Array Observatory. The NectarCAM camera equipping the MSTs is sensitive to gamma rays in the energy range of approximately 100 GeV to 10 TeV. The camera consists of 1,855 pixels, grouped into modules of 7 pixels each.
To accurately reconstruct real data acquisitions,...
The ALPACA experiment, a new air-shower array in Bolivia to observe cosmic rays and gamma rays in the energy range between TeV to PeV, aims to survey PeVatron candidates in the southern sky, including the Galactic Center. The ALPAQUITA experiment, a prototype of ALPACA, has 97 scintillation detectors with an area of 1 m$^2$ and began data taking in April 2023.
In the ALPACA collaboration, the...
The High-energy Underwater Neutrino Telescope (HUNT) is a proposed next-generation neutrino observatory with an instrumented volume of approximately 30 cubic kilometers, aiming to discover dozens of the high-energy neutrino point sources in ten years. We investigate a multiple-cluster design and optimize the array geometry, varying parameters such as radius, height, and the number of clusters,...
Ground-based imaging air Cherenkov telescopes (IACTs) detect Cherenkov light produced by the interaction of very high-energy (VHE) gamma rays with the upper atmosphere. Building on the success of the current generation of IACTs, the next-generation VHE gamma-ray observatory, the Cherenkov Telescope Array Observatory (CTAO), is being developed at two sites: one in the Northern Hemisphere, at...
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 IceCube Neutrino Observatory is a neutrino detector located beneath the glacial ice at the South Pole. The IceCube Upgrade is currently being deployed, adding seven new strings to the central region of the existing array deep under the ice. Each string contains around 100 newly designed optical modules (mDOMs and D-Eggs) along with calibration devices. One of the primary goals of 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 TRopIcal DEep-sea Neutrino Telescope (TRIDENT), a next-generation neutrino telescope in the South China Sea, requires precise position measurements to exploit the timing capabilities of hybrid digital optical modules (hDOMs), ensuring the pointing capability of the detector. This poster presents a preliminary design of the TRIDENT acoustic positioning system, which includes the acoustics...
While seismology remains the primary tool for studying Earth's internal structure, neutrinos offer two complementary and independent approaches to probe our planet's composition. At energies above TeV, the increasing neutrino interaction cross section enables Earth tomography through flux attenuation measurements—a technique that has already yielded experimental results. Conversely,...
Compact binary mergers, detected in gravitational waves since 2015, are candidate sources for astrophysical neutrinos in the GeV regime from proton-proton and proton-neutron collisions. This contribution presents the results of the search for such a signal using mergers detected during the fourth observing run of the LIGO, Virgo and KAGRA interferometers. We use the dense infill array at the...
While the evidence of high-energy neutrinos was established a decade ago and confirmed independently by the observation of an ultra-high-energy neutrino recently announced, the origin of these neutrinos is not yet fully identified. Gamma-ray bursts (GRBs) have long been one of the most promising candidate emitters of such neutrinos. Despite not having led to a significant detection in...
Stripped envelope supernovae (SESNe) are pivotal high-energy astrophysical phenomena that illuminate the final stages of massive star evolution and the mechanisms driving stellar explosions. Utilizing the James Webb Space Telescope (JWST) across optical to mid-infrared (MIR) wavelengths, our research provides comprehensive observations of SESNe, enabling a deeper understanding of their ejecta...
We present a novel methodology for extracting firn ice properties using reflection coefficients (`S11') of antennas lowered into boreholes. Experiments like the Radio Neutrino Observatory in Greenland (RNO-G) require precise firn index of refraction profiles for accurate reconstructions of incident neutrinos. Coupled with Finite-Difference Time Domain (FDTD) simulations, a depth-dependent S11...
The IceCube Neutrino Observatory is currently the largest and most sensitive detector for astrophysical neutrinos and has pioneered the field of high-energy neutrino astronomy. Despite being designed with the primary goal of identifying astrophysical TeV neutrinos and their corresponding sources, recent studies, utilising the DeepCore subdetector, have shown IceCube's proficiency in being...
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...
Bulk Data Management, including the long-term archiving of massive datasets, is critical for advancing high-energy gamma-ray astrophysics research by ensuring data accessibility and scientific reproducibility. Within the Cherenkov Telescope Array Observatory (CTAO), managing and preserving petabyte-scale data poses unique challenges. To address these challenges, we present our prototyping...
The goal of the Radar Echo Telescope (RET) collaboration is to detect ultra-high-energy neutrinos via in-ice radar techniques. To this end, the RET collaboration has been aiming to demonstrate the radar echo method in-situ with the Radar Echo Telescope for Cosmic Rays (RET-CR) experiment, located in Greenland. RET-CR utilised secondary in-ice particle cascades - generated by high-energy cosmic...
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...
The ASTRI Mini-Array is an international project, led by the Italian "Istituto Nazionale di Astrofisica" (INAF), with the aim to build and operate a facility sensitive to very high-energy gamma-rays in the 1-200 TeV energy range. It consists of an array of nine small-sized (4-m diameter) and large field of view (~10°) Imaging Atmospheric Cherenkov Telescopes under deployment at the...
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...
The Calorimetric Electron Telescope (CALET) is a high-energy astroparticle physics experiment on the International Space Station (ISS). CALET, with its 30 radiation-length deep calorimeter designed for the measurement of cosmic-ray electrons, is also sensitive to the astrophysical gamma-ray flux from ~1 GeV to ~1 TeV. Launched to the Japanese Experiment Module - Exposed Facility in August...
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 Cherenkov Telescope Array Observatory (CTAO) is going to be the leading observatory for very-high-energy gamma rays over the next decades. Its unique sensitivity, wide field of view, and rapid slewing capability make the CTAO especially suited to study transient astrophysical phenomena. The CTAO will analyse its data in real time, responding to external science alerts on transient events...
This study presents an updated search for magnetic monopoles using data collected over a 14-year period (2008–2022) by the ANTARES neutrino telescope. The interaction of magnetic monopoles with matter was modeled using the Kasama, Yang, and Goldhaber cross-section. Upper limits on the flux of magnetic monopoles were derived for velocities both above and below the Cherenkov threshold. No events...
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...
Astrophysical neutrinos may be produced during the coalescence of compact objects, in particular those involving neutron stars. Such mergers have been observed through gravitational wave detections by LIGO-Virgo-KAGRA interferometers. The ANTARES and KM3NeT deep-sea neutrino telescopes are sensitive to neutrino interactions in a wide range of energies, from MeV to PeV. This contribution...
The discovery of VHE emission from the Crab pulsar and, more recently, multi-TeV emission from the Vela pulsar have challenged our current understanding of the emission mechanisms of these sources. Studying pulsar emission at TeV energies allows us to understand the engines that power some of the most extreme accelerators in the Galaxy and their roles as potential positron factories. We...
Accreting neutron stars are expected to emit a redshifted 2.2 MeV line resulting from neutron capture. The detection of this line would provide constraints on the neutron star equation of state and offer insights into the nuclear reactions within the neutron star atmosphere. We have developed a theoretical framework aimed at predicting the optimal X-ray luminosity for the detection of this...
In the past few years, extremely extended TeV radiation from middle-aged pulsars has been observed in multiple sources across several experiments. However, whether millisecond pulsars(MSPs) have the ability to produce TeV radiation remains an open question. The newly discovered source J0216+4237 by LHAASO is an example of an MSP that produces extended TeV radiation. In this research, we use...
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...
While IceCube’s detection of astrophysical neutrinos at energies up to a few PeV has opened a new window to our Universe, much remains to be discovered regarding these neutrinos’ origin and nature. In particular, the difficulty of differentiating electron- and tau-neutrino charged-current (CC) events limits our ability to measure precisely the flavor ratio of this flux. The Tau Air-Shower...
The identification of astrophysical sources responsible for high-energy cosmic neutrinos has long been a challenge. A significant milestone was achieved with the blazar TXS 0506+056, which was found to be in a flaring state of high gamma-ray emission and associated at the 3sigma level with a 290 TeV neutrino detected by IceCube in September 2017. This discovery motivated deeper exploration of...
Future space detectors for Ultra High Energy neutrinos and cosmic rays will utilize Cherenkov telescopes to detect forward-beamed Cherenkov light produced by charged particles in Extensive Air Showers. A Cherenkov detector can be equipped with an array of Silicon Photo-Multiplier (SiPM) pixels, which offer several advantages over traditional photomultiplier tubes (PMTs). SiPMs are compact,...
Radio detection of ultra-high-energy cosmic rays and neutrinos has emerged as a promising next-generation experimental technique. The polar regions, particularly Antarctica and the Arctic, are considered ideal sites due to their exceptionally low background noise. However, one of the primary challenges in operating experiments in these remote locations is ensuring a stable power supply. While...
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...
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...
We present a comprehensive analysis of the spectro-temporal characteristics of the X-ray variabilities from black hole X-ray binary 4U1630–472 during its three outbursts (2018, 2020, and 2021) as observed by NICER. We detected 27 Quasi-Periodic Oscillations (QPOs), out of which 25 were observed during the 2021 outburst. In this study, we specifically focus on the relationship between...
In this contribution, we investigate the cosmological evolution of quasars with the KM3NeT neutrino telescope. Quasars are amongst the most luminous non-transient extragalactic sources accelerating particles to relativistic velocities. These particles will produce gamma-rays as well as neutrinos. The quasar luminosities and number densities within the universe are evolving with redshift, and...
IceCube Upgrade, which will be completed in the beginning of 2026, will enhance the sensitivity of the current IceCube in the GeV range and improve understanding of the ice properties. Around 700 new modules will be deployed deep in the ice along seven strings within a horizontal circle of roughly 100 m in diameter, and most of the modules are spaced 3 m vertically. IceCube Upgrade consists...
Abstract: The VERITAS Imaging Atmospheric Cherenkov Telescope array (IACT) has been augmented with high-speed focal plane electronics to allow Stellar Intensity Interferometry (SII) observations of bright (OBA) stars in the visible waveband (416 nm). VSII observations have also served as a testbed to explore hardware and analysis improvements to advance the technique's sensitivity. VSII has...
The Pacific Ocean Neutrino Experiment (P-ONE) is a planned cubic-kilometer-scale Cherenkov neutrino telescope that will be deployed off the West Coast of Canada. To evaluate the performance of the telescope and support future analyses, it is essential to have accurate simulations of neutrino interactions and background sources. This contribution provides an overview of the current status of...
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...
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 "solar metallicity problem" has persisted in solar structure modeling for over three decades. A precise measurement of CNO neutrinos could offer definitive evidence to resolve this issue, as their flux directly reflects the abundance of heavy elements in the solar core. The recent detection of CNO neutrinos by the Borexino experiment using a liquid scintillator detector marked a...
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 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...
IceCube-Gen2 is a proposed next-generation neutrino facility at the South Pole, designed to expand upon the achievements of the pioneering IceCube observatory. This contribution provides a comprehensive review of efforts to ensure the sustainability of IceCube-Gen2 and minimize its environmental impact in Antarctica and in world-wide collaboration activities. Scenarios for overcoming...
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...
The Probe of Extreme Multi-Messenger Astrophysics Balloon with Radio mission (PBR) will point above Earth's limb to measure PeV energy cosmic rays, and record star images to monitor optical focusing in situ. PBR will point below Earth's limb to search for earth-skimming neutrinos. PBR will also measure EeV energy cosmic rays by tilting as far down as the nadir direction. All of these searches...
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,...
KM3NeT is a network of underwater Cherenkov neutrino telescopes currently under construction at two sites in the Mediterranean Sea. ARCA, located offshore the Sicilian Coast (Italy), is optimized for the detection of high energy cosmic neutrinos, while ORCA situated off the coast of Toulon (France), is designed for studying atmospheric neutrinos.
Both detectors consist of vertical strings,...
The ASTRI Mini-Array is an international project led by the Italian "Istituto Nazionale di Astrofisica" (INAF) to build and operate an array of nine Imaging Atmospheric Cherenkov Telescopes designed to study Galactic and extragalactic sources in the multi-TeV energy range. It is located at the "Observatorio del Teide" (Tenerife, Spain) where the first telescope, ASTRI-1, is already operative....
The LHAASO detection of the very high energy (VHE) emission component from gamma-ray bursts (GRBs) up to the multi-TeV regime proved the importance of ground-based gamma-ray facilities in exploring the physics of these enigmatic objects up to the extreme energies. In recent years, significant efforts in improving the strategies for follow-up of transient events have been performed within the...
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...
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 ASTRI Mini-Array is an international project aimed to build, deploy, and operate an array of nine small-sized dual-mirror Imaging Atmospheric Cherenkov Telescopes (IACTs) at the Observatorio del Teide (Tenerife, Spain). The array is designed to perform deep Galactic and extragalactic gamma-ray observations in the 1–200 TeV energy band, in synergy with other ground-based gamma-ray...
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 Einstein Telescope (ET) will be the next generation gravitational wave observatory in Europe with a sensitivity reaching beyond the CMB into the dark era of the Universe. Each corner of the triangular baseline design is the center of two interferometers with 10 km long arms, one operated at room temperature, the other one with mirrors at cryogenic temperatures of 10 – 15 K that reduce 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 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...
The KM3NeT neutrino telescope, under deployment in the Mediterranean Sea, consists of two detectors: KM3NeT/ARCA and KM3NeT/ORCA. Despite sharing the same hardware, their geometries are optimized for different neutrino energy ranges: ARCA targets high-energy neutrinos above the TeV scale, while ORCA focuses on the GeV-TeV range. Additionally, both are sensitive to MeV neutrinos from supernova...
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 KM3NeT (Cubic Kilometre Neutrino Telescope) is an underwater high-energy neutrino telescope consists of two detectors located offshore Toulon, France, at 2500 m water depth, called ORCA (Oscillation Research with Cosmics in the Abyss) and offshore Capo Passero, Italy, at 3500 m water depth called ARCA (Astronomy Research with Cosmics in the Abyss). The basic element of the detector is the...
The LEGEND (Large Enriched Germanium Experiment for Neutrinoless double beta Decay) experiment aims at the detection of the neutrinoless double beta decay, which, if observed, would lead to groundbreaking implications in neutrino physics and in cosmology. Located at Laboratori Nazionali del Gran Sasso, Italy, the experiment will discover if the neutrino is a Majorana particle (i.e. it...
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...
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...
An innovative optical module (OM) with segmented light-sensitive area has been developed for IceCube-Gen2 that will take neutrino astronomy at the South Pole to the next level. It builds on the successful features of the mDOM and D-Egg modules of IceCube Upgrade while adapting to the smaller borehole diameter of IceCube-Gen2. The newly developed OM, which is being tested in IceCube Upgrade,...
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...
The ASTRI Mini-Array (MA) is an international project led by the Italian National Institute for Astrophysics (INAF) to construct and operate an observatory dedicated to gamma-ray astronomy in the TeV spectral band. The ASTRI MA is currently under construction and will consist of an array of nine innovative Imaging Atmospheric Cherenkov Telescopes located at the Teide Astronomical Observatory,...
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 Cherenkov Telescope Array Observatory (CTAO) will greatly improve upon sensitivities in the field of very-high-energy gamma-ray astrophysics. The CTAO northern site (CTAO-North, La Palma, Spain) currently hosts LST-1 with the remaining three large-sized telescopes (LSTs) expected in mid-2026 and one medium-sized telescope (MST) expected in late-2026. The CTAO southern site (CTAO-South,...
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 Small-Sized Telescopes (SSTs) will be a key component of the Cherenkov Telescope Array Observatory (CTAO), the next-generation ground-based gamma-ray observatory in the energy range from tens of GeV to hundreds of TeV. They will focus on the highest energies, from about 1 TeV to at least 300 TeV, with a planned deployment of at least 37 and potentially up to 70 units at the southern site...
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...
Core-collapse supernova emits 99% of its gravitational energy in a short burst of neutrinos with energies around 10 MeV.
This neutrino signal, if detected, can be used as a probe for physics in the stellar evolution and collapse process,
as well as neutrino properties such as flavor transformations.
The SuperNova Early Warning System (SNEWS) is an global network of neutrino and dark...
The origin of cosmic rays in PeV energy regime is currently among the hot unsolved problems both in the observational and theoretical aspects. For the sub -PeV gamma-ray astronomy, a project of the TAIGA-100 installation with an area of 100 km2 and an energy threshold of 300-400 TeV is being developed. The installation of such a site will allow for the study of galactic PeVatrons at a...
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,...
The KM3NeT neutrino telescope consists of two detectors: ARCA, at 3500m depth offshore Capo Passero, Sicily, and ORCA, at 2500m depth offshore Toulon. Both detectors consist in a 3D-grid of Detection Units (DUs), each with 18 Digital Optical Modules (DOMs), anchored on the seabed and linked to the shore station via optical fibers. Each DOM houses 31 3-inch photomultiplier tubes (PMTs) and the...
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 POEMMA-Balloon with Radio (PBR) is a NASA mission designed to study Ultra-High-Energy Cosmic Rays (UHECRs) and Very-High-Energy Neutrinos (VHENs) from a balloon platform. Serving as a precursor to the planned POEMMA (Probe of Extreme Multi-Messenger Astrophysics) satellite mission, PBR will be launched aboard a NASA Super Pressure Balloon for a targeted flight as long as 50 days at an...
Dark matter (DM) candidates, such as Weakly Interacting Massive Particles (WIMPs), can annihilate to Standard Model particles, subsequently producing gamma rays. In this work, we search for DM-induced gamma-ray signals from Coma Berenices dwarf spheroidal galaxy (CBe dSph) using approximately 25 hours of observations carried out by the Major Atmospheric Gamma Imaging Cherenkov (MAGIC)...
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...
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...
A novel compact charge readout method based on Field Programmable Gate Array (FPGA) voltage-referenced receiver was proposed. In the highly integrated charge readout method, it consists of a dual-polarity Charge-to-Time Converter (dQTC) and digital FPGA. We refer to this new FPGA-based charge measurement method as FPGA-dQTC. In the FPGA-dQTC method, an FPGA input receiver serves as a voltage...
Gamma-ray astronomy is able to acquire large data volumes that astronomers
use to draw scientific conclusions from. Ensuring the possibility of accessing and
utilizing this data also after the lifetime of currently running
experiments requires the use of a standardized data format.
Following the data standardization format proposed by the gamma-ray astronomy
community, we show the first...
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...
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...
Baikal-GVD is a gigaton-scale neutrino telescope being constructed in
Lake Baikal. The detector presently includes 13 independent detector
sub-arrays (clusters), each consisting of 8 or 9 strings, each of
which holds 36 optical modules. High-energy muon neutrino interaction
through the W-boson exchange results in the production of muons with
range of propagation reaching many kilometers....
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...
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...
TRIDENT is a future, next-generation neutrino telescope to be built in the South China Sea, designed to discover astrophysical neutrino sources and probe fundamental physics over astronomical distances. An optimal trigger system is needed to ensure events of interest are recorded with high efficiency, while also minimizing the rate of backgrounds during data transmission. For example,...
To effectively capture authentic neutrino events in the project of High-Energy Underwater Neutrino Telescope (HUNT), a robust triggering scheme is required to filter out background noise while maximizing the preservation of neutrinos. This paper proposes algorithms for various types of neutrino events. We have designed two triggering models: a spherical shell intersection model and a...
The origins of ultra-high-energy particles remain one of the most profound mysteries in astrophysics. If nearby transient sources of ultra-high-energy particles exist, we might expect correlated emission of neutrinos and photons, arriving in close temporal and spatial coincidence. The IceCube Neutrino Observatory, located at the South Pole, is sensitive to neutrinos from TeV to EeV energies,...
The extended ultra-high-energy (UHE) gamma-ray source HAWC J1844–034 is closely associated with two other sources, HAWC J1843–032 and HWC J1846–025. Moreover, other gamma-ray observatories like HESS, LHAASO, and Tibet ASγ have detected UHE gamma-ray sources whose spatial positions coincide with the position of HAWC J1844–034. The UHE gamma-ray data from several observatories aid analysis of...
In recent years the number of known sources emitting very- and ultra-high-energy gamma-rays has increased significantly thanks to facilities such as LHAASO and HAWC. Many of the observed sources are still unidentified or poorly constrained due to the limited angular resolution of these instruments; however, it is now ascertained that approximately half of them have a middle-aged pulsar in...
A decade of gamma-ray observations from the Milky Way's centre has provided hints of the existence of a Galactic accelerator, the so-called PeVatron, capable of generating cosmic rays up to PeV energy scales. These hints are based on the observation of a gamma-ray energy spectrum from the dense gas clouds at the centre of our galaxy, which follow an energy spectrum with no detected cut-off up...
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...
IDMAR is a multidisciplinary underwater research infrastructure currently under
construction in the abyssal depths of the Mediterranean Sea, off the
southeastern coast of Sicily. It integrates innovative sensors for real-time
studies in the underwater environment. One of IDMAR’s primary use cases is ARCA,
the Cherenkov detector being developed by the KM3NeT Collaboration as part of
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 Square Kilometre Array (SKA) is a next-generation radio telescope, and upon construction in 2030 the world's most sensitive one. SKA will comprise a low frequency component with almost 60$\,$000 radio antennas on an extremely densely instrumented area of about 1$\,$km$^2$ located in Australia. Sensitive to the radio emission in the 50 to 350$\,$MHz band, these astonishing dimensions offer...
Majority of supernova remnants expand into a complex environment of the stellar wind bubble blown up either by their progenitor or their companion star, where forward shock might interact with various density inhomogeneities. Such interactions would cause formation of fast reflected shocks propagating back and forth between the forward shock, the contact discontinuity in the interior of the...
Occultations, the covering up of one celestial body by another celestial body, have been used in astronomy for millennia to learn about the sun and moon. Since 2018, VERITAS has implemented a program to detect predicted asteroid occultations, where an asteroid covers up a star. VERITAS has attempted to observe close to 100 occultations to date and successfully observed 12 occultations. With...
While high-energy astrophysical neutrinos are well-established, their flavor composition remains relatively unconstrained. In IceCube, long muon tracks from $\nu_\mu$-CC interactions are easily identified but the detector geometry does not allow sufficient granular resolution to distinguish the cascade-type events. The Neutron Echo - a delayed light signal in the detector from neutron capture...
Observations of the Galactic Center with Imaging Atmospheric Cherenkov Telescopes (IACTs) have identified HESS J1745-290, a very-high-energy (VHE; > 100 GeV) gamma-ray source that is spatially coincident with the dynamical center of the Milky Way Galaxy. The emission detected by IACTs appears point-like (< 0.1 deg) and exhibits a pronounced suppression in its energy-differential spectrum at...
X-ray binaries (XRBs) are strong hard X-ray emitters and among the most common sources in the Galactic plane within the 20–100 keV energy range. A handful of XRBs, both transient and persistent, have also been detected as gamma-ray emitters by Fermi/LAT and AGILE-GRID above 30 MeV (e.g., Cyg X-3, Cyg X-1, and V404 Cyg), yet the origin of this gamma-ray emission remains largely unknown....
