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Related papers: Unidentified EGRET Sources

200 papers

We present a study on the possible association of unidentified $\gamma$-ray sources in the Third EGRET (3EG) catalog with different types of galactic objects such as Wolf-Rayet and Of stars, supernova remnants (SNRs), and OB associations…

Astrophysics · Physics 2008-11-26 G. E. Romero , P. Benaglia , Diego F. Torres

We revisit the association of unidentified Galactic plane EGRET sources with tracers of recent massive star formation and death. Up-to-date catalogs of OB associations, SNRs, young pulsars, HII regions and young open clusters were used in…

Astrophysics · Physics 2009-10-28 I. -A. Yadigaroglu , Roger W. Romani

Diffuse Galactic gamma-ray emission is produced in interactions of cosmic rays with gas and ambient photon fields and thus provides us with an indirect measurement of cosmic rays in various locations in the Galaxy. The diffuse gamma-ray…

Astrophysics · Physics 2007-05-23 Martin Pohl

We propose that some of the high-latitude unidentified EGRET gamma-ray sources could be the result of gravitational lensing amplification of the innermost regions of distant, faint, active galactic nuclei. These objects have gamma-ray…

Astrophysics · Physics 2009-11-07 Diego F. Torres , Gustavo E. Romero , Ernesto F. Eiroa

The EGRET instrument has measured detailed photon spectra between 30 MeV and 10 GeV, which are represented by means of single power-law fits for sources in the 3EG catalog. However, various sources show indications of spectral cutoffs at…

Astrophysics · Physics 2007-05-23 O. Reimer , D. L. Bertsch

Using a likelihood analysis (updated since McLaughlin & Cordes 2000) and EGRET detections, upper limits and diffuse background measurements, we find a best-fit luminosity law for the gamma-ray pulsar population. We find that roughly 30 of…

Astrophysics · Physics 2007-05-23 M. A. McLaughlin , J. M. Cordes

Population studies of EGRET gamma-ray sources indicate that there is a distinctive population of bright sources at low galactic latitudes. The sources have a distribution consistent with that of young galactic objects, with a concentration…

Astrophysics · Physics 2009-11-10 Valenti Bosch-Ramon , Gustavo E. Romero , Josep M. Paredes

Over half of GeV gamma-ray sources observed by the EGRET experiment have not yet been identified as known astronomical objects. There is an isotropic component of such unidentified sources, whose number is about 60 in the whole sky. Here we…

Astrophysics · Physics 2009-10-31 Tomonori Totani , Tetsu Kitayama

Unassociated Fermi-LAT sources provide a population with discovery potential. We discuss efforts to find new source associations for this population, and summarize the successes to date. We discuss how the measured gamma-ray properties of…

High Energy Astrophysical Phenomena · Physics 2012-06-13 Elizabeth C. Ferrara , Roopesh Ojha , Maria Elena Monzani , Nicola Omodei

One of the main scientific objectives of the recent Fermi mission is investigating the origin of the unidentified gamma-ray sources (UGSs). Despite the large improvements of Fermi in the gamma-ray source localization with respect to the…

High Energy Astrophysical Phenomena · Physics 2013-03-15 F. Massaro , R. D'Abrusco , A. Paggi , N. Masetti , M. Giroletti , G. Tosti , Howard A. Smith

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

We studied the problematic of uncertainties in the diffuse gamma radiation apparent in stacking analysis of EGRET data at low Galactic latitudes. Subsequently, we co-added maps of counts, exposure and diffuse background, and residuals, in…

Astrophysics · Physics 2008-11-26 Analia N. Cillis , Olaf Reimer , Diego F. Torres

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

We present a compilation of data on the 22 tentatively identified gamma-ray sources from the Third EGRET Catalog which may be detected by the next-generation imaging atmospheric Cherenkov telescopes.

Astrophysics · Physics 2009-11-06 D. Petry , O. Reimer

We present new theoretical estimates of the relative contributions of unresolved blazars and star-forming galaxies to the extragalactic gamma-ray background (EGB) and discuss constraints on the contributions from alternative mechanisms such…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Floyd W. Stecker , Tonia M. Venters

The origin of the diffuse extragalactic, high-energy gamma-ray background (EGRB) filling the Universe remains unknown. The spectrum of this extragalactic radiation, as measured by the EGRET on-board CGRO, is well-fit by a power law across…

Astrophysics · Physics 2009-11-07 Caleb A. Scharf , Reshmi Mukherjee

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

We compute the variation of the beaming fraction with the efficiency of high energy gamma-ray production in the outer gap pulsar model of Romani and Yadigaroglu. This allows us to correct the fluxes observed for pulsars in the EGRET band…

Astrophysics · Physics 2009-10-22 I. -A. Yadigaroglu , Roger W. Romani

We report an evidence for the first time that merging clusters of galaxies are a promising candidate for the origin of high galactic-latitude, steady unidentified EGRET gamma-ray sources. Instead of using past optical catalogs of…

Astrophysics · Physics 2008-11-26 Wataru Kawasaki , Tomonori Totani

Microquasars are X-ray binary systems with non-thermal radio emission originated in jet-like features. They are attractive sites for gamma-ray production, since relativistic particles in the jet should traverse locally strong both photon…

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