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Related papers: Spectral cutoffs in EGRET gamma-ray sources

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We investigated the MeV properties of 173 unidentified or only tentatively identified EGRET sources listed in the third EGRET catalogue, by analyzing the simultaneously collected COMPTEL MeV data for each individual source. The sources can…

Astrophysics · Physics 2009-11-10 S. Zhang , W. Collmar , W. Hermsen , V. Schönfelder

Although the majority of gamma-ray sources still remain unidentified, we have various kinds of information to characterize the observational properties of unidentified EGRET sources. Despite astronomical properties like locations of…

Astrophysics · Physics 2016-01-27 Olaf Reimer

One of the principal results obtained by the EGRET experiment aboard the Compton Gamma-Ray Observatory (CGRO) was the detection of several Gamma-ray bursts (GRBs) above 100 MeV. The broad-band spectra obtained for these bursts gave no…

Astrophysics · Physics 2009-10-31 Matthew G. Baring

At least three pulsars in supernova remnants were detected at E > 100 MeV by EGRET on the Compton Gamma Ray Observatory. Efforts to search for additional pulsars in the EGRET data have been unsuccessful due to limited statistics. An example…

Astrophysics · Physics 2007-05-23 D. J. Thompson , S. W. Digel , P. L. Nolan , O. Reimer

The EGRET instrument on the Compton Gamma Ray Observatory (1991-2000) has positively detected high energy gamma-ray emission from more than 67 active galaxies of the blazar class. The majority of the EGRET blazars are flat-spectrum radio…

Astrophysics · Physics 2009-11-06 R. Mukherjee

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,…

In this paper some of the brightest GeV sources observed by the Fermi-LAT were analysed, focusing on their spectral cut-off region. The sources chosen for this investigation were the brightest blazar flares of 3C~454.3 and 3C~279 and the…

High Energy Astrophysical Phenomena · Physics 2017-01-11 C. Romoli , A. M. Taylor , F. Aharonian

The all-sky survey in high-energy gamma rays (E$>$30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma-Ray Observatory provides a unique opportunity to examine in detail the diffuse gamma-ray…

Astrophysics · Physics 2011-05-05 P. Sreekumar

Context. A considerable fraction of the gamma-ray sources discovered with the Energetic Gamma-Ray Experiment Telescope (EGRET) remain unidentified. The EGRET sources that have been properly identified are either pulsars or variable sources…

We present a catalog of point gamma-ray sources detected by the EGRET detector aboard the Compton Gamma Ray Observatory. We have used the whole gamma-ray dataset of reprocessed photons at energies above 100 MeV together with new Galactic…

Astrophysics · Physics 2009-11-13 Jean-Marc Casandjian , Isabelle A. Grenier

Published EGRET spectra from blazars extend only to 10 GeV, yet EGRET has detected approximately 2000 gamma-rays above 10 GeV of which about half are at high Galactic latitude. We report a search of these high-energy gamma-rays for…

Astrophysics · Physics 2009-11-06 Brenda L. Dingus , David L. Bertsch

The Fermi-LAT telescope has measured the extragalactic gamma-ray background (EGB) generated by the ensemble of all extragalactic sources. The energy distribution of the EGB is well described as a power-law with a spectral index…

High Energy Astrophysical Phenomena · Physics 2020-09-09 Paolo Lipari

In the course of its operation, the EGRET experiment detected high-energy gamma ray sources at energies above 100 MeV over the whole sky. In this communication, we search for large-scale anisotropy patterns among the catalogued EGRET…

Astrophysics · Physics 2007-05-23 Luis Anchordoqui , Thomas McCauley , Thomas Paul , Olaf Reimer , Diego F. Torres

Recent observations with atmospheric Cherenkov telescope systems such as H.E.S.S. and MAGIC have revealed a large number of new sources of very-high-energy (VHE) gamma-rays from 100 GeV - 100 TeV, mostly concentrated along the Galactic…

Astrophysics · Physics 2008-11-26 S. Funk , O. Reimer , D. F. Torres , J. A. Hinton

The limited angular resolution of gamma-ray telescopes prevents the straight identification of the majority of the sources detected so far. This is particularly true for the low latitude, probably galactic ones, only 10 % of which has been…

While the definitive detection of gamma-rays from known supernova remnants (SNRs) remains elusive, the collection of unidentified EGRET sources that may be associated with SNRs has motivated recent modelling of TeV emission from these…

Astrophysics · Physics 2007-05-23 Matthew G. Baring , Donald C. Ellison , Isabelle Grenier

One of the principal results obtained by the Compton Gamma Ray Observatory relating to the study of gamma-ray bursts was the detection by the EGRET instrument of energetic ($>$100 MeV) photons from a handful of bright bursts. The most…

Astrophysics · Physics 2007-05-23 Matthew G. Baring

The study of the high-energy (MeV-GeV) part of GRBs spectrum can play a crucial role in investigating the physics of the prompt emission, but it is often hampered by low statistic and the paucity of GeV observations. In this work, we…

High Energy Astrophysical Phenomena · Physics 2024-05-29 M. E. Ravasio , G. Ghirlanda , G. Ghisellini

A review of the main characteristics of low-latitude sources in the third EGRET catalog is presented. There are 75 unidentified gamma-ray sources detected by EGRET at less than 10 degrees from the galactic plane. About a half of these…

Astrophysics · Physics 2007-05-23 Gustavo E. Romero

The EGRET telescope has repeatedly observed 3EG J1835+5918 as a bright and steady source of high-energy gamma-ray radiation which has not yet been indentified. EGRET data from CGRO observation cycle 1 to 7 have been reanalysed above 100 MeV…

Astrophysics · Physics 2009-11-06 O. Reimer , K. T. S. Brazier , A. Carraminana , G. Kanbach , P. L. Nolan , D. J. Thompson
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