Prof.
Kenji Yoshida
(Shibaura Institute of Technology)
30/07/2015, 15:30
GA-EX
Poster contribution
The Fermi-LAT 3rd source catalog (3FGL) provides spatial, spectral, and temporal properties for 3033 gamma-ray sources. While 2041 sources in the 3FGL are associated with AGNs (58% of the total), pulsars (5%) and the other classes (4%), 992 sources (33%) remain as unassociated sources. In recognizing source classes for unassociated gamma-ray sources of the Fermi-LAT source catalogs, various...
Stefan Klepser
(DESY)
30/07/2015, 15:30
GA-IN
Poster contribution
Mr
Ori Weiner
(Columbia University)
30/07/2015, 15:30
GA-EX
Poster contribution
In imaging atmospheric Cherenkov telescope arrays (IACTs), the standard method of statistically inferring the existence of a source is based on the maximum likelihood method of Li&Ma (1983). We will present a new statistical approach, also based on maximum likelihood theory, which takes into account a priori knowledge of the source light curve. This approach is especially useful for...
Felix Spanier
(North-West University)
30/07/2015, 15:30
GA-TH
Poster contribution
Active Galactic Nuclei have been in the focus of gamma-ray telescopes for the past years. With the ever growing sample of AGN the need for physically motivated, self-consistent modeling is also growing.
The major questions to be answered by models are: What are the main constituents of AGN jets? What are the acceleration mechanisms? Are AGN possible accelerators for UHECR and possible...
Robert Brose
(DESY)
30/07/2015, 15:30
GA-TH
Poster contribution
RX J1713-3946 is the brightest shell-type supernova remnant (SNR) of the TeV gamma-ray sky. Earlier Fermi-LAT results on low energy gamma-ray emission suggested that, despite large uncertainties in the background determination, the spectrum is inconsistent with a hadronic origin. We update the GeV-band spectra using improved estimates for the diffuse galactic gamma-ray emission and more than...
Marcos López Moya
(University Complutense of Madrid)
30/07/2015, 15:30
GA-IN
Poster contribution
The MAGIC telescopes were built with the aim of achieving the lowest possible energy threshold among the current generation of Cherenkov telescopes. This was mandatory to detect sources with emission mainly below 100 GeV, as distant AGNs and pulsars. In 2009, the second MAGIC telescope started operation, and in the last years, a major upgrade of the system took place. One of the main...
Dr
Thomas Weisgarber
(for the HAWC Collaboration)
30/07/2015, 15:30
GA-EX
Poster contribution
The High Altitude Water Cherenkov (HAWC) Gamma Ray Observatory monitors the gamma-ray sky in the 100 GeV to 100 TeV energy range with >95% uptime and unprecedented sensitivity for a survey instrument. The HAWC Collaboration has implemented an online flare monitor that detects episodes of rapid flaring activity from extragalactic TeV sources in the declination band from -26 to 64 degrees. This...
Helene Laffon
(CENBG)
30/07/2015, 15:30
GA-EX
Poster contribution
The millisecond pulsar (MSP) luminosity distribution is useful to address e.g. contributions to the distribution of the diffuse positrons and gamma rays within our Galaxy. Gamma-ray luminosity versus spin-down power (Edot) is also a key observable to constrain emission models. The Shklovskii effect consists of an artificial increase of the apparent period derivative value (Pdot) over the...
Prof.
Vladimir Vassiliev
(University of California Los Angeles)
30/07/2015, 15:30
GA-IN
Poster contribution
The design of a 9.5-m prototype Schwarzschild-Couder telescope (pSCT) with an aplanatic two-mirror optical system has been developed to evaluate its capabilities for the future Cherenkov Telescope Array Observatory (CTAO). The construction of this novel imaging atmospheric Cherenkov telescope (IACT) is scheduled for early autumn of 2015 at the Fred Lawrence Whipple Observatory in Southern...
Susumu Inoue
(Institute for Cosmic Ray Research, University of Tokyo)
30/07/2015, 15:30
GA-TH
Poster contribution
There is mounting evidence for the widespread existence of ultra-fast outflows in active galactic nuclei, which are powerful outflows of baryonic material approaching mildly relativistic velocities, observed as variable, blue-shifted X-ray absorption lines of ionized heavy elements. Occurring in both radio-loud and radio-quiet objects, they are plausibly interpreted as winds driven by the...
Ms
Xilu Wang
(University of Illinois at Urbana and Champaign)
30/07/2015, 15:30
GA-TH
Poster contribution
In star-forming galaxies, gamma rays are mainly produced through the collision of high-energy protons in cosmic rays and protons in the interstellar medium (ISM) (i.e. cosmic ray-induced π0 γ-radiation). For a “normal” star-forming galaxy like the Milky Way, most cosmic rays escape the Galaxy before such collisions, but in starburst galaxies with dense gas and huge star formation rate, most...
Amanda Weinstein
(Iowa State University)
30/07/2015, 15:30
GA-EX
Poster contribution
The Cygnus region hosts one of the most remarkable star-forming regions in the Milky Way. Indeed, the total mass in molecular gas of the Cygnus X complex exceeds 10 times the total mass of all other nearby star-forming regions. Surveys at all wavelengths, from radio to gamma-rays, reveal that Cygnus contains such a wealth and variety of sources---supernova remnants (SNRs), pulsars, pulsar...
Nepomuk Otte
(Georgia Institute of Technology)
30/07/2015, 15:30
GA-IN
Poster contribution
We present a development of a novel 11328 pixel silicon photomultiplier (SiPM) camera for use with a ground-based Cherenkov telescope with Schwarzschild-Couder optics as a possible mid-size telescope for the Cherenkov Telescope Array (CTA), which is the next generation very-high-energy gamma-ray observatory. . The finely pixelated camera samples air-shower images with more than twice the ...
Lucie Gerard
30/07/2015, 15:30
GA-EX
Poster contribution
The galactic and extragalactic surveys are two of the main proposed legacy projects of the Cherenkov Telescope Array (CTA). Considering Cherenkov telescopes field of view (<10°), the time needed for those projects is large. The many telescopes of CTA will allow taking full advantage of new pointing modes in which telescopes point slightly offset from one another. This divergent pointing mode...
Raphaël Chalmé-Calvet
(LPNHE)
30/07/2015, 15:30
GA-IN
Poster contribution
In 2012, the High Energy Stereoscopic System (H.E.S.S.) was expanded by a fifth telescope (CT5). With an enormous effective mirror diameter of 28 m, CT5 is able to detect the Cherenkov light of very faint gamma-ray air showers, thereby significantly lowering the energy threshold of this telescope compared to the other four telescopes. Extracting as much information as possible from the...
Silvia Vernetto
(Istituto Nazionale di Astrofisica)
30/07/2015, 15:30
GA-EX
Poster contribution
The gamma ray sky at energies above a few tens of TeV is almost completely unexplored. Sources of photons above ~30 TeV must however exist because cosmic rays are accelerated in the Milky Way at least up to the knee energy. Photon emission in this energy range, with a high degree of confidence, has an hadronic origin and traces the proton and nuclei acceleration sites. Gamma ray astronomy...
Dr
Dorothee Hildebrand
(ETH Zurich)
30/07/2015, 15:30
GA-IN
Poster contribution
FACT is the first Imaging Air Cherenkov Telescope to use solid-state photosensors
(G-APD/SiPM) in order to measure the light flashes induced by air-showers.
A vital part of the telescope system is the atmosphere.
Typically, external devices such as LIDARs are used to quantify the quality of the atmospheric condition.
Due to the exceptional stability of G-APD sensors, a different...
Dominik Neise
(ETH Zurich)
30/07/2015, 15:30
GA-EX
Poster contribution
The First G-APD Cherenkov Telescope (FACT) is the first operational test of the performance of silicon photomultipliers (SiPM) in Cherenkov Astronomy. These novel photon detectors promised to be an inexpensive and robust alternative for vacuum photomultiplier tubes, but had never been applied in an imaging airshower cherenkov telescope (IACT) up to now. For more than three years FACT has...
Mr
Jens Buß
(TU Dortmund)
30/07/2015, 15:30
GA-EX
Poster contribution
The First G-APD Cherenkov telescope (FACT) is the first operational telescope of its kind with a camera equipped with silicon photon detectors (G-APD aka. SiPM). SiPMs have a high photon detection efficiency (PDE), while being more robust to bright light conditions than the commonly used photo-multiplier tubes. This technology has allowed us to increase the duty cycle beyond that of the...
523.
FACT – Novel mirror alignment using Bokeh and enhancement of the VERITAS SCCAN alignment method
Sebastian Mueller
(ETH Zuerich)
30/07/2015, 15:30
GA-IN
Poster contribution
Imaging Air Cherenkov Telescopes, including the First G-APD Cherenkov Telescope (FACT), use
segmented reflectors. These offer large and fast apertures for little resources.
However, one challenge of segmented reflectors is the alignment of the single mirrors to gain a
sharp image. For Cherenkov telescopes, high spatial and temporal resolution is crucial to
reconstruct air shower events...
Valerie Connaughton
30/07/2015, 15:30
GA-EX
Poster contribution
Owing to its wide sky coverage and broad energy range, the Fermi Gamma-ray Burst Monitor (GBM) is an excellent observer of the transient hard X-ray sky. GBM detects about 240 triggered Gamma-Ray Bursts (GRBs) per year, including over 30 which also trigger the Swift Burst Alert Telescope (BAT). The number of GRBs seen in common with Swift is smaller than expected from the overlap in sky...
Francesco Loparco
(Universita e INFN, Bari (IT))
30/07/2015, 15:30
GA-EX
Poster contribution
We have measured the gamma-ray emission spectrum of the Moon using a the data collected by the Large Area Telescope onboard the Fermi satellite during its first 77 months of operation, in an energy range from 30 MeV up to a few GeV. We have developed a full Monte Carlo simulation describing the interactions of cosmic rays with the Moon surface and the subsequent production of gamma rays using...
Nepomuk Otte
(Georgia Institute of Technology)
30/07/2015, 15:30
GA-IN
Poster contribution
Low-cost and low-power digitization systems become increasingly important in particle-physics
and particle-astrophysics experiments as the number of channels is continuously rising. Specialized readout concepts have been developed in the past that aimed at lower costs and made detector systems with many ten thousand channels feasible. As the number
of channels in experiments is still on the...
Dr
Joachim Hahn
(MPIK)
30/07/2015, 15:30
GA-TH
Poster contribution
GAMERA is a new open-source C++ package which handles the spectral modelling of non-thermally emitting astrophysical sources in a simple and modular way. It allows the user to devise time-dependent models of leptonic and hadronic particle populations in a general astrophysical context (including SNRs, PWNs and AGNs) and to compute their subsequent photon emission. Moreover, this package also...
Tova Yoast-Hull
(University of Wisconsin-Madison)
30/07/2015, 15:30
GA-TH
Poster contribution
Regions of intense star-formation naturally generate high number densities of cosmic rays and as such, they are of particular interest as potential contributors to the extragalactic gamma-ray background (EGRB) and as potential sources of very high-energy cosmic rays (VHECRs). While models of the starburst contribution to the EGRB often assume cosmic rays are confined in starbursts, cosmic...
Mr
Rafal Wojaczynski
(Department of Astrophysics, University of Lodz)
30/07/2015, 15:30
GA-TH
Poster contribution
We present results of the analysis of the Fermi-LAT data from low-luminosity Seyfert galaxies, whose X-ray spectra are consistent with predictions of the hot flow (ADAF) model. We use our precise hot flow model (fully GR and with a Monte Carlo computation of radiative processes) to fit the X-ray data and then we estimate the gamma-ray flux from hadronic processes in the two-temperature plasma...
Wlodek Bednarek
(University of Lodz)
30/07/2015, 15:30
GA-TH
Poster contribution
We consider a simple scenario for the accretion of matter onto rotating, magnetised neutron star in order to understand the processes in the inner pulsar magnetosphere during the transition stage between different accretion modes. We analyse a quasi-spherical accretion process onto rotating, magnetized compact object in order to search for radiative signatures which could accompany the...
Dr
Satoru Takahashi
(Kobe University)
30/07/2015, 15:30
GA-IN
Poster contribution
The observation of high-energy cosmic gamma-rays provides us with direct information of high-energy phenomena in the universe. Currently, AGILE and Fermi-LAT are observing gamma-ray sky and many understandings are being brought to us. However, past and current observations have significant limitations. The improvement of angular resolution and polarization sensitivity is one of keys for a...
Mr
Keita OZAKI
(Kobe University)
30/07/2015, 15:30
GA-IN
Poster contribution
GRAINE is a balloon-borne experiment to observe cosmic gamma-ray with precise angular resolution and polarization sensitivity.
Main gamma-ray detector is nuclear emulsion which can record three dimensional charged particle track with sub-micron position accuracy. We use multi-stage shifter technique in order to give time information to penetrating tracks of nuclear emulsion. Arrival...
Heike Prokoph
(Linnaeus University)
30/07/2015, 15:30
GA-EX
Poster contribution
Blazars are the most abundant class of known extragalactic very-high-energy (VHE, E>100 GeV) gamma-ray sources. However, one of the biggest difficulties in investigating their VHE emission resides in their limited number, since less then 60 of them are known by now.
In this contribution we report on the H.E.S.S. observations of the BL Lac object PKS 1440-389. This source has been selected...
Andrew Smith
(University of Maryland, College Park)
30/07/2015, 15:30
GA-IN
Poster contribution
The High-Altitude Water Cherenkov (HAWC) Observatory was completed and began full operation in early 2015. The detector consists of an array of 300 water tanks, each containing ~200 tons of purified water and instrumented with 4 PMTs. Located at an elevation of 4100m a.s.l. near the Sierra Negra volcano in central Mexico, HAWC has a threshold for gamma-ray detection well below 1 TeV and a...
Jean-Francois Glicenstein
(CEA)
30/07/2015, 15:30
GA-EX
Poster contribution
PKS 1830-211 is a lensed blazar located at z=2.5. The recent addition of a 28 m Cherenkov telescope (CT5) to the H.E.S.S. array extended the experiment's sensitivity towards low energies, providing access to gamma-ray energies down to 30 GeV. Data towards PKS1830-211 were taken with CT5 in August 2014, following a flare alert by the Fermi collaboration at the beginning of the month. The...
Piotr Banasiński
(University of Lodz)
30/07/2015, 15:30
GA-TH
Poster contribution
During the quiet $\gamma$-ray state of blazars the high energy emission is likely to be produced in the extended part of the inner jet in which the conditions can change significantly. Therefore, homogeneous SSC model is not expected to describe correctly the quiet state emission features. We consider inhomogeneous SSC model for the large part of the inner jet in which synchrotron and IC...
Masaki Mori
(Ritsumeikan University)
30/07/2015, 15:30
GA-EX
Poster contribution
The microquasar 1E 1740.7-2942, discovered by the Einstein satellite, is located near the Galactic Center at an angular distance of 50' from Sgr A*, and the brightest X-ray source above 20 keV in the Galactic Center region. It has extended radio lobes reaching distances of up to a few parsecs and its core radio emission is variable. In X-ray energies it shows the spectral and timing properties...
Mr
LIU Cheng
(IHEP, CAS), Mr
QIAN Xiangli
(IHEP, CAS)
30/07/2015, 15:30
GA-IN
Poster contribution
The underground muon detector with water Cherenkov technique is constructed as the upgrad of the Tibet air shower array, aiming at a higher sensitivity for gamma-ray observation. In one of the modules (MD-A), the full-sealing large Tyvek bag is used as a closed? container. As the MD-A has been operated for more than one year, the long term stability of the performance of such detector is reported.
Ms
Priyadarshini Bangale
(MPI for Physics, Munich)
30/07/2015, 15:30
GA-EX
Poster contribution
M 87 is the closest extragalactic VHE object located in the Virgo cluster of galaxies at a distance of ~16 Mpc (redshift z=0.00436). It is the first and brightest radio galaxy detected in the TeV regime, well studied from radio to X-ray energies. The structure of its relativistic plasma jet, which is misaligned with respect to our line of sight, is spatially resolved in X-ray (Chandra),...
Prof.
Hanrong Wu
(Institute of High Energy Physics, CAS), Prof.
Huihai He
(Institute of High Energy Physics, CAS)
30/07/2015, 15:30
GA-IN
Poster contribution
Detection of GeV photons from GRBs is crucial in understanding the most violent phenomenon in our universe. Due to the limited effective area of space-born experiment, very few GRBs are detected with GeV photons. Large area EAS experiments at high altitude can reach a much larger effective area around 10 GeV, for which single particle technique is usually used to lower the threshold energy but...
Dr
Lucy Fortson
(University of Minnesota)
30/07/2015, 15:30
GA-EX
Poster contribution
Intermediate-frequency-peaked BL Lacertae objects (IBLs) are a class of blazars characterized by a spectral energy distribution (SED) with a lower-energy synchrotron peak than a majority of extragalactic sources detected by ground-based imaging atmospheric Cherenkov telescopes (IACTs). Because of this shift in the SED, the peak gamma-ray flux falls outside the very-high-energy regime (VHE,...
Victor Zabalza
(University of Leicester)
30/07/2015, 15:30
GA-TH
Poster contribution
The ultimate goal of the observation of nonthermal emission from astrophysical
sources is to understand the underlying particle acceleration and evolution
processes, and few tools are publicly available to infer the particle
distribution properties from the observed photon spectra from X-ray to VHE gamma
rays. Naima is an open source Python package that provides models for
non-thermal...
Jean-Francois Glicenstein
(CEA)
30/07/2015, 15:30
GA-IN
Poster contribution
NectarCAM is a camera proposed for the medium-sized telescopes of the Cherenkov Telescope Array (CTA) covering the central energy range of ~100 GeV to ~30 TeV. It has a modular design and is based on the NECTAr chip, at the heart of which is a GHz sampling Switched Capacitor Array and 12-bit Analog to Digital converter. The camera will be equipped with 265 7-photomultiplier modules, covering...
Bayarto Lubsandorzhiev
(Institute for Nuclear Research of RAS)
30/07/2015, 15:30
GA-IN
Poster contribution
We present new concepts of timing calibration systems for large-scale Cherenkov arrays in astroparticle physics experiments like Cherenkov arrays detecting extensive air showers (EAS) and water Cherenkov neutrino arrays. The concepts are based on a fast powerful LED light source on board of a pilotless remotely controlled helicopter in case of EAS Cherenkov arrays and on multiple LED sources...
Dr
Laurent Bouchet
(IRAP)
30/07/2015, 15:30
GA-TH
Poster contribution
We present $^{26}Al$ map distribution throughout the Galaxy measured by the SPI spectrometer aboard the INTEGRAL observatory. This emission at 1.809 MeV is associated with the $^{26}Al$ decay and to the production of heavy elements in the Galaxy.
The only available $^{26}Al$ map to date has been released, more than fifteen years ago, thanks to the COMPTEL instrument.
However, at the...
Max Ludwig Ahnen
(ETH Zurich)
30/07/2015, 15:30
GA-EX
Poster contribution
The On-Off problem, aka. Li-Ma problem, is a statistical problem where a measured rate is the sum of two parts. The first is due to a signal and the second due to a background, both of which are unknown. Mostly frequentist solutions are being used, but they are only adequate for high count numbers. When the events are rare such an approximation is not good enough. Indeed, in high-energy...
Ulisses Barres
(Centro Brasileiro de Pesquisas Físicas)
30/07/2015, 15:30
GA-EX
Poster contribution
n 2012, Fermi/LAT gamma-ray and radio observations have registered the largest ever recorded flaring episodes from the blazar Markarian 421.
The unprecedented activity state of the source has remained high, and much above the normal behaviour seem from the source also for the year 2013, characterising a dramatic and long-lasting change of behaviour in the emission of the object. This unique...
Dr
Jean-Laurent Dournaux
(GEPI. CNRS, Observatoire de Paris)
30/07/2015, 15:30
GA-IN
Poster contribution
The Cherenkov Telescope Array (CTA) project aims to create the next generation Very High Energy gamma-ray telescope array. It will be devoted to the observation of gamma rays over a wide band of energy, from 20 GeV to 300 TeV. Two sites are foreseen, one in the northern and the other in the southern hemisphere, allowing the viewing of the whole sky. The southern site will be equipped with...
608.
Performance studies of the new stereoscopic Sum-Trigger-II of MAGIC after one year of operation
Dr
Francesco Dazzi
(Max-Planck-Institute for Physics Munich)
30/07/2015, 15:30
GA-IN
Poster contribution
MAGIC is a stereoscopic system of two Imaging Air Cherenkov Telescopes (IACTs) located at La Palma (Canary Islands, Spain) and working in the field of very high energy gamma-ray astronomy. It makes use of a traditional digital trigger with an energy threshold of around 55 GeV. A novel trigger strategy, based on the analogue sum of signals from partially overlapped patches of pixels, leads to a...
Markus Holler
(LLR - Ecole Polytechnique)
30/07/2015, 15:30
GA-IN
Poster contribution
The High Energy Stereoscopic System (H.E.S.S.) is an array of five Imaging Atmospheric Cherenkov Telescopes (IACTs) designed to detect and image cosmogenic gamma-rays with very high energies. Originally consisting of just four identical IACTs (CT1-4) with an effective mirror diameter of 12$\,$m each, it was expanded with a fifth IACT (CT5) with a mirror diameter of 28$\,$m in 2012. Being the...
Sun Zhandong
(Southwest Jiaotong University)
30/07/2015, 15:30
GA-IN
Poster contribution
A prototype array for the LHAASO-KM2A, which consists of 39 detector units, was set up at the Yangbajing cosmic ray observatory(4300m a.s.l., Tibet, P.R. China) and has been in stable operation since Octoter 2014. In this paper, we present the performances of the prototype electromagnetic particle detector and the prototype array.
Dr
Nachiketa Chakraborty
(Max-Planck-Institut fuer Kernphysik)
30/07/2015, 15:30
GA-EX
Poster contribution
Flaring states of the BL Lac object, Mrk 501 were observed by the High Energy Stereoscopic System (H.E.S.S.) during 2012 and 2014. Observations in 2014 recorded flux levels higher than one Crab unit and revealed rapid variability at very high energies ($\sim$ 2-20 TeV). The high statistics afforded by the flares allowed us to probe the presence of minutes timescale variability and study its...
Gregory Richards
(Georgia Institute of Technology)
30/07/2015, 15:30
GA-EX
Poster contribution
In recent years, the Fermi-LAT gamma-ray telescope has detected a population of over 160 gamma-ray pulsars, which has enabled the detailed study of gamma-ray emission from pulsars at energies above 100 MeV. Further, since the surprising detection of the Crab pulsar in very high-energy (VHE; E > 100 GeV) gamma rays by the MAGIC and VERITAS collaborations, there has been an ongoing effort in the...
Dr
Paolo Goldoni
(APC/CEA-Irfu)
30/07/2015, 15:30
GA-EX
Poster contribution
Blazars are active galactic nuclei, and the most numerous High Energy (HE) and Very High Energy (VHE)gamma-ray emitters. Their optical emission is often dominated by non-thermal, and, in the case of BL Lacs, featureless continuum radiation. This renders the determination of their redshift extremely difficult. Indeed as of today only about 50% of gamma-ray blazars have a measured spectroscopic...
Mr
Ramin Marx
(MPIK Heidelberg)
30/07/2015, 15:30
GA-IN
Poster contribution
The Cherenkov Telescope Array (CTA) will be a ground-based gamma-ray observatory with full-sky coverage in the very-high energy (VHE) regime. It is proposed to consist of more than 100 telescopes and should produce large amounts of data, possibly exceeding the volume of current VHE Imaging Atmospheric Cherenkov Telescopes by ~two orders of magnitude. This volume of data represents a new...
Anna Franckowiak
(SLAC)
30/07/2015, 15:30
GA-EX
Poster contribution
Supernovae (SNe) exploding in a dense circumstellar medium (CSM) are hypothesized to accelerate cosmic rays in collisionless shocks and emit GeV gamma rays and TeV neutrinos on a time scale of several months. We perform the first systematic search for gamma-ray emission in Fermi LAT data in the energy range from 100 MeV to 300 GeV from the ensemble of SNe exploding in dense CSM. We study a...
marcos lopez
(University Complutense of Madrid)
30/07/2015, 15:30
GA-EX
Poster contribution
Geminga pulsar appears to be one of the most promising candidates to emit VHE gamma-ray pulsed emission.
In order to detect the third pulsar with power-law spectral component above of the measured cutoff,
after Crab and Vela, we analyzed 63 hours of data taken with MAGIC. To discuss the connection with
HE gamma rays, 6 years of Fermi-LAT data were also analyzed. No significant pulsation was...
Mrs
Sara Coutiño
(INAOE)
30/07/2015, 15:30
GA-TH
Poster contribution
The extragalactic background light (EBL) is all the electromagnetic energy released by resolved and unresolved extragalactic sources since the recombination era. Its intensity and spectral shape provide information about the evolution of galaxies throughout cosmic history. Since direct observations of the EBL are very difficult to perform, the study of the interaction between the low energy...
Dr
Bo Gao
(Institute of High Energy Physics,CAS), Dr
Hanrong Wu
(Institute of High Energy Physics,CAS), Mr
Huicai Li
(Naikai University), Dr
Mingjun Chen
(Institute of High Energy Physics,CAS), Prof.
Zhiguo Yao
(Institute of High Energy Physics,CAS)
30/07/2015, 15:30
GA-EX
Poster contribution
The Large High Altitude Air Shower Observatory (LHAASO) will be constructed at Mt. Haizi in Sichuan Provice, China. As a major component of the LHAASO project, the Water Cherenkov Detector Array (WCDA) is designed to record air showers produced by cosmic rays and gamma rays in the energy range from 100 GeV to 100 TeV. Complementing the Imaging Atmospheric Cherenkov Telescopes with large...
Anita Reimer
(University of Innsbruck)
30/07/2015, 15:30
GA-TH
Poster contribution
The non-thermal spectra of jetted Active Galactic Nuclei
(AGN) show a variety of shapes and degrees of curvature in
their low and high energy components. From some of the
brightest Fermi-LAT blazars prominent spectral breaks at
a few GeV have been regularly detected which is
inconsistent with conventional cooling effects. We
propose that the broad variety of spectral shapes
including...
Alexander Ziegler
(ECAP, University of Erlangen-Nuremberg, Germany)
30/07/2015, 15:30
GA-TH
Poster contribution
Observations of the Galactic Center with the H.E.S.S. instrument have led to the detection of an extended region of diffuse TeV $\gamma$-ray emission.
The origin of this emission is not yet fully understood, although the spatial correlation between the density distribution of giant molecular clouds located at the center of our Galaxy and the intensity of the observed $\gamma$-ray excess...
Dr
Yi Zhang
(IHEP)
30/07/2015, 15:30
GA-IN
Poster contribution
The large field of view and low threshold energy are highly desirable properties for the ground based observations of high energy GRBs. However, larger field of view is difficult to achieve for current imaging atmospheric cherenkov telescopes (IACT), and the threshold below O(100)GeV is also a challenging for current EAS arrays. An alternative solution is to adopt the refractive optics system...
Igor Oya
(DESY Zeuthen)
30/07/2015, 15:30
GA-IN
Poster contribution
The Cherenkov Telescope Array (CTA) is the next-generation atmospheric Cherenkov gamma-ray observatory. CTA will consist of two installations, one in each hemisphere, containing tens of telescopes of different sizes. The CTA performance requirements and the inherent complexity associated with the operation, control and monitoring of such a large distributed multi-telescope array leads to new...
Bo Gao
(Institute of High Energy Physics, Chinese Academy of Sciences), Dr
Mingjun Chen
(Institute of High Energy Physics, Chinese Academy of Sciences)
30/07/2015, 15:30
GA-IN
Poster contribution
A Large High Altitude Air Shower Observatory (LHAASO) is planned to be built in next year. As an important component of LHAASO project, Water Cherenkov Detector Array (WCDA) is a high sensitivity gamma ray and cosmic ray detector, which is mainly to survey the northern sky for VHE gamma ray sources. Currently, the R&D is quite finished, including a prototype water Cherenkov detector and an...
Dr
Anne Lemière
(APC)
30/07/2015, 15:30
GA-EX
Poster contribution
The Very High Energy Galactic Center Ridge was revealed by H.E.S.S. in 2006, after subtraction of the point sources HESS J1745-290 possibly associated with Sgr A* and HESS J1747-281 associated with the composite supernova remnant G0.09+0.1. The hard spectrum of the Ridge emission and its spatial correlation with the local gas density suggest that the emission is due to collisions of multi-TeV...
Prof.
Luobu Danzeng
(Tibet University), Prof.
Tianlu Chen
(Tibet University)
30/07/2015, 15:30
GA-IN
Poster contribution
Sub-100GeV to TeV is a crucial energy window in gamma ray astronomy because of its important role connecting the space experiments and the ground-based observations. The observations in this energy range are expected to provide rich information about the high energy emission from GRBs and AGNs, with which EBL can be measured, and knowledge about the galaxy formation and the evolution of the...
Dr
Francesco de Palma
(INFN and Pegaso University)
30/07/2015, 15:30
GA-EX
Poster contribution
While supernova remnants (SNRs) are widely thought to be powerful cosmic-ray accelerators, indirect evidence comes from a small number of well-studied cases. Here we systematically determine the gamma-ray emission detected by the Fermi Large Area Telescope (LAT) from all known Galactic SNRs, disentangling them from the sea of cosmic-ray generated photons in the Galactic plane. Using LAT data...
Prof.
Leonid Kuzmichev
(SINP MSU)
30/07/2015, 15:30
GA-IN
Poster contribution
The aim of the TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is to construct in the Tunka Valley (50 km from Lake Baikal) a complex, hybrid array for multi–TeV gamma-ray astronomy and CR studies. The array will consist of a wide angle Cherenkov array - Tunka-HiSCORE with ~3 km2 area, a net of IACT telescopes and muon detectors with total area of up to 2000 m2....
Wlodek Bednarek
(University of Lodz)
30/07/2015, 15:30
GA-TH
Poster contribution
Recently very energetic millisecond pulsar, J1823-3021A, has been discovered to emit pulsed GeV gamma-rays in the globular cluster NGC 6624. Assuming that this pulsar injects relativisitic leptons into its surrounding (as expected from modelling of radiative processes within the inner pulsar magnetosphere), we calculate the minimum level of expected TeV gamma-ray emission produced by these...
Andrea De Franco
(University of Oxford)
30/07/2015, 15:30
GA-IN
Poster contribution
The Gamma-ray Cherenkov Telescope (GCT) is proposed to be part of the Small Size Telescope (SST) array of CTA (the Cherenkov Telescope Array).
Its dual mirror optical design allows the use of a compact camera of diameter roughly 0.4m, the curved focal plane of which is equipped
with 2048 pixels of ~0.2° angular size, resulting in a field of view of ~9°.
The GCT camera is designed to...
Dr
Troy Porter
(Stanford University)
30/07/2015, 15:30
GA-TH
Poster contribution
The Fast Radiation transport Numerical Kalculation for Interstellar Emission (FRaNKIE) code is a Monte Carlo code for calculating the electromagnetic emissions in galaxies. The code is highly parallel and optimised for both CPUs and co-processor accelerators. The code takes into account the interaction of the photon field with the interstellar medium in a self-consistent way, providing a...
Dr
Fabian Schüssler
(Irfu, CEA-Saclay)
30/07/2015, 15:30
GA-EX
Poster contribution
Based on fundamental particle physics processes like the production and subsequent decay of pions in interactions of high-energy particles, close connections exist between the acceleration sites of high-energy cosmic rays and the emission of high-energy gamma rays, high-energy neutrinos and other messengers like gravitational waves. In most cases these connections provide both spatial and...
Dr
Alberto Dominguez
(Clemson University)
30/07/2015, 15:30
GA-EX
Poster contribution
The extragalactic background light (EBL) contains fundamental cosmological and galaxy evolution information. Very high energy observations of extragalactic sources, such as blazars, can be used to extract this information because of the pair-production interaction between gamma-ray and EBL photons. We present (almost) simultaneous broad-band data of a dozen BL Lacs that allow us to make the...
Ruben Lopez-Coto
(Institut de Fisica d'Altes Energies - IFAE)
30/07/2015, 15:30
GA-IN
Poster contribution
Imaging atmospheric Cherenkov telescopes such as the MAGIC telescopes are built to achieve the lowest possible energy threshold. The trigger system of these telescopes is one of the most important parts to achieve it. The main problem when decreasing the energy triggered by an IACT is the rapid increase of accidental triggers caused by the ambient light and the after pulses of the...
Dr
Masato TAKITA
(Institute for Cosmic Ray Research, the University of Tokyo)
30/07/2015, 15:30
GA-IN
Poster contribution
We plan to build a large (approximately 10,000 m**2) water Cherenkov-
type muon detector array under the existing Tibet air shower array at
4,300 m above sea level, to observe 10-1000 TeV gamma rays from
cosmic-ray accelerators in our Galaxy with wide field of view
at very low background level. A gamma-ray induced air shower has
significantly less muons compared with a cosmic-ray induced...
Elisa Prandini
(University of Geneva)
30/07/2015, 15:30
GA-EX
Poster contribution
The blazar PG1553+113 is an active galaxy with uncertain redshift detected at very high energies (VHE; E > 100 GeV) both during high and quiescent states. We have observed with the MAGIC telescopes from La Palma PG 1553+113 at VHE since 2005, making this blazar one of the best studied MAGIC sources.
Recently, the Fermi/LAT collaboration has reported the detection of a hint of a ~2-year...
Dr
Bo Gao
(Institute of High Energy Physics, Chinese Academy of Sciences), Dr
Hanrong Wu
(Institute of High Energy Physics, Chinese Academy of Sciences), Mr
Huicai Li
(School of Physics, Nankai University), Dr
Mingjun Chen
(Institute of High Energy Physics, Chinese Academy of Sciences), Ms
Xiaojie Wang
(Institute of High Energy Physics, Chinese Academy of Sciences), Prof.
Zhiguo Yao
(Institute of High Energy Physics, Chinese Academy of Sciences)
30/07/2015, 15:30
GA-IN
Poster contribution
As a major component of the LHAASO project, the main physical goal of the Water Cherenkov Detector Array (WCDA) is to survey the northen sky for VHE gamma ray sources. One of the key issues to fulfill this goal is the angular resolution and the pointing precision of the detector, which depends much on the time calibration of the whole array. In this paper, a new time calibration technique...
Michael Zacharias
30/07/2015, 15:30
GA-TH
Poster contribution
The detection of very rapid flares on the order of minutes in blazars has spawned a lot of theoretical activity. Even though many models take time-dependent effects (such as varying magnetic fields, etc) into account, a time-dependent nature of the injection process is usually omitted. In this presentation it is shown using the standard one-zone model that time-dependent injection has strong...
Dr
Bo Gao
(IHEP, Beijing), Dr
Hanrong Wu
(IHEP, Beijing), Mr
Huicai Li
(School of Physics, Univeristy of Nankai), Dr
Mingjun Chen
(IHEP, Beijing), Ms
Xiaojie Wang
(IHEP, Beijing), Prof.
Zhiguo Yao
(IHEP, Beijing)
30/07/2015, 15:30
GA-IN
Poster contribution
The Water Cherenkov Detector Array (WCDA) of the LHAASO project is to be built in Daocheng, Sichuan Province of China. It comprises of 4 neighboring ponds, each in dimension of 150 m $\times$ 150 m, and divided into 900 cells, with a PMT in each cell. A triggerless scheme is to be adopted for the data acquiring system, in which all the single channel signals are synchronized and transferred to...
Thanh Nguyen
30/07/2015, 15:30
GA-EX
Poster contribution
The Crab pulsar and plerion are some of the brightest and best studied non-thermal astrophysical sources. The recent discovery of pulsed gamma-ray emission above 100 GeV from the Crab pulsar with VERITAS (the Very Energetic Radiation Imaging Telescope Array System) challenges commonly accepted pulsar emission models and puts the gamma-ray emission region far out in the magnetosphere – close to...
Dr
Donghwa Kang
(Karlsruhe Institute of Technology)
30/07/2015, 15:30
GA-EX
Poster contribution
KASCADE-Grande was a multi-detector array to measure individual air showers of cosmic rays in the energy range of 10 PeV up to 1 EeV. Based on full data sets measured by KASCADE-Grande, an upper limit to the flux of ultra-high energy gamma rays in primary cosmic rays is determined. The analysis is performed by selecting air showers with low muon contents due to a small fraction of secondary...
Henrike Fleischhack
(DESY)
30/07/2015, 15:30
GA-EX
Poster contribution
The cores of Ultra-Luminous InfraRed Galaxies (ULIRGs) are very dense environments, with a high rate of star formation and hence supernova explosions. They are thought to be sites of cosmic-ray acceleration, and are predicted to emit $\gamma$-rays in the GeV to TeV range. So far, no ULIRG has been detected in $\gamma$-rays. Arp 220, the closest ULIRG to Earth, has been well studied, and...
David Kieda
(University of Utah)
30/07/2015, 15:30
GA-EX
Poster contribution
In this talk, we report the VERITAS discovery of very high energy (E > 100 GeV) gamma ray emission from RGB J2243+204, previously detected in radio and X-ray. This source is also consistent with the Fermi-LAT gamma-ray source 1FHL J2244.0+2020. RGB J2243+204 has been classified both as an intermediate-frequency-peaked BL Lac object and as a high-frequency-peaked BL Lac object in the past....
Matteo Cerruti
(Harvard-Smithsonian Center for Astrophysics)
30/07/2015, 15:30
GA-EX
Poster contribution
The high-frequency-peaked BL Lac object 1ES 0806+524 (z=0.138) was discovered as a source of very-high-energy (VHE, E>100 GeV) gamma-ray photons in 2008 with the VERITAS telescope array, at a level of 1.8% of the Crab Nebula flux above 300 GeV. Since then, VERITAS has continued observing the source over multiple seasons, significantly improving the significance of the detection. We report the...
Karlen Shahinyan
(University of Minnesota)
30/07/2015, 15:30
GA-EX
Poster contribution
HESS J1943+213 is a very-high-energy (VHE; > 100 GeV) gamma-ray point source detected during the H.E.S.S. Galactic Plane Survey. Radio, infrared, X-ray, and GeV gamma-ray counterparts have been identified for HESS J1943+213; however, the classification of the source is still uncertain. Recent publications have argued primarily in favor of either an extreme BL Lac object behind the Galactic...
Ralph Bird
(UCD Dublin)
30/07/2015, 15:30
GA-EX
Poster contribution
Diffuse gamma rays are tracers of cosmic rays, providing information on their origin and diffusion. M 31 (the Andromeda Galaxy) is the closest spiral galaxy to the Milky Way (d = 750 kpc) and is very well studied at all wavelengths, thus it is a prime target for the study of diffuse gamma-ray emission. The very-high-energy (VHE, E > 100 GeV) gamma-ray observatory VERITAS has conducted 45 hours...
Dr
Bo Gao
(Institute of High Energy Physics, CAS), Prof.
Chunxu Yu
(School of Physics, Nankai University), Dr
Hanrong Wu
(Institute of High Energy Physics, CAS), Mr
Huicai Li
(School of Physics, Nankai University), Dr
Mingjun Chen
(Institute of High Energy Physics, CAS), Ms
Xiaojie Wang
(Institute of High Energy Physics, CAS), Prof.
Zhiguo Yao
(Institute of High Energy Physics, CAS)
30/07/2015, 15:30
GA-IN
Poster contribution
The Large High Altitude Air Shower Observatory (LHAASO) project is to be built at Daocheng, Sichuan Province, 4400 m a.s.l., in a few years. As one of the major components of the LHAASO project, LHAASO-WCDA, a water Cherenkov detector array with an area of 90000 m2, contains around 400,000 tons of purified water. To gain full knowledge of the water Cherenkov technique and to investigate the...
