Related papers: Observation of Multi-Tev Diffuse Gamma Rays from t…
The potential of an array of imaging atmospheric Cherenkov telescopes to detect gamma-ray sources in complex regions has been investigated. The basic characteristics of the gamma-ray instrument have been parametrized using simple analytic…
As recently shown, Fermi-LAT measurements of the diffuse gamma-ray emission from the Galaxy favor the presence of a smooth softening in the primary cosmic-ray spectrum with increasing Galactocentric distance. This result can be interpreted…
The High-Altitude Water Cherenkov (HAWC) Observatory, located 4100 m above sea level near Sierra Negra (19$^\circ$ N) in Mexico, is sensitive to gamma rays and cosmic rays at TeV energies. The arrival direction distribution of cosmic rays…
The ~70 unidentified sources of the EGRET sky survey may be one of its most important legacies. The identification of these sources at other wavelengths is critical to understanding their nature. Many have flat spectra out to 10 GeV which,…
The spatial extension of a gamma-ray source is an essential ingredient to determine its spectral properties as well as its potential multi-wavelength counterpart. The capability to spatially resolve gamma-ray sources is greatly improved by…
Because accretion and merger shocks in clusters of galaxies may accelerate particles to high energies, clusters are candidate sites for the origin of ultra-high-energy (UHE) cosmic-rays. A prediction was presented for gamma-ray emission…
Recently, detections of a high-energy gamma-ray source at the position of the Galactic center have been reported by multiple gamma-ray telescopes, spanning the energy range between 100 MeV and 100 TeV. Analysis of these signals strongly…
The imaging atmospheric Cherenkov array H.E.S.S. recently discovered an extended source in the 0.4$-$10 TeV energy range, HESS J1303-631. We obtained a 5 ks observation with the ACIS-I array on the Chandra X-ray observatory that does not…
We present an analysis of COMPTEL observations made between November 1991 and May 1994 of 2CG 135+01, a bright gamma-ray source located near the Galactic plane. At energies above 1 MeV, an excess consistent with the position of 2CG 135+01…
The search for Gamma Ray Burst (GRB) emission in the energy range 1-100 GeV in coincidence with the satellite detection has been carried out using the Astrophysical Radiation with Ground-based Observatory at YangBaJing (ARGO-YBJ)…
The high-energy Diffuse Gamma-Ray Background (DGRB) is expected to be produced by unresolved isotropically distributed astrophysical objects, potentially including dark matter annihilation or decay emissions in galactic or extragalactic…
The diffuse gamma radiation arising from the interaction of cosmic ray particles with matter and radiation in the Galaxy is one of the few probes available to study the origin of the cosmic rays. Milagro is a water Cherenkov detector that…
We report on observations of the sky region around the unidentified TeV gamma-ray source TeV J2032+4130 carried out with the Whipple Observatory 10 m atmospheric Cherenkov telescope for a total of 65.5 hrs between 2003 and 2005. The…
The ARGO-YBJ experiment is a full-coverage air shower detector located at the Yangbajing Cosmic Ray Observatory (Tibet, People's Republic of China, 4300 m a.s.l.). The high altitude, combined with the full-coverage technique, allows the…
The Fermi bubbles are structures observed in gamma rays at GeV energies, emanating from the central region of our galaxy and extending up to 8.5 kpc above and below the galactic plane. While initial studies showed a flat brightness across…
Gamma-ray induced air showers are notable for their lack of muons, compared to hadronic showers. Hence, air shower arrays with large underground muon detectors can select a sample greatly enriched in photon showers by rejecting showers…
The preliminary design of the new space gamma-ray telescope GAMMA-400 for the energy range 100 MeV - 3 TeV is presented. The angular resolution of the instrument, 1-2{\deg} at E{\gamma} ~100 MeV and ~0.01^{\circ} at E{\gamma} > 100 GeV, its…
Gamma ray source detection above 30TeV is an encouraging approach for finding galactic cosmic ray origins. All sky survey for gamma ray sources using wide field of view detector is essential for population accumulation for various types of…
GRAPES-3 is a mid-altitude (2200 m) and near equatorial ($11.4^{\circ}$ North) air shower array, overlapping in its field of view for cosmic ray observations with experiments that are located in Northern and Southern hemispheres. We analyze…
The last measurement of the diffuse emission spectrum of the Milky Way in the megaelectronvolt (MeV) photon energy range was performed by CGRO/COMPTEL more than 20 years ago. We report a new analysis with the spectrometer SPI aboard…