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相关论文: Variability of EGRET Gamma-Ray Sources

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B2013+370 and B2023+336 are two blazars at low-galactic latitude that were previously proposed to be the counterparts for the EGRET unidentified sources, 3EG J2016+3657 and 3EG J2027+3429. Gamma-ray emission associated with the EGRET…

高能天体物理现象 · 物理学 2015-06-03 E. Kara , M. Errando , W. Max-Moerbeck , E. Aliu , M. Bottcher , P. Fortin , J. P. Halpern , R. Mukherjee , A. C. S. Readhead , J. L. Richards

We present the results of a new model calculation of the gamma-ray background produced by unresolved blazars, using the second EGRET catalogue and taking account of flaring. These results are compared to the preliminary gamma-ray background…

天体物理学 · 物理学 2009-10-28 F. W. Stecker , M. H. Salamon

Luminosities and uxes of the expected population of galactic gamma-ray pulsars become foreseeable if physical distributions at birth and evolutive history are assigned. In this work we estimate the contribution of pulsar uxes to the…

天体物理学 · 物理学 2015-06-24 E. Bisesi

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…

天体物理学 · 物理学 2007-05-23 D. J. Thompson , S. W. Digel , P. L. Nolan , O. Reimer

In recent years, blazar surveys at radio and X-ray energies have greatly increased our understanding of this type of active galaxy. The combination of multi-wavelength data has shown that blazars follow a well defined sequence in terms of…

天体物理学 · 物理学 2007-05-23 I. de la Calle Perez

Using three epochs of VLA observations of the Galactic Plane in the first quadrant taken ~15 years apart, we have conducted a search for a population of variable Galactic radio emitters in the flux density range 1-100 mJy at 6 cm. We find…

星系天体物理 · 物理学 2015-05-18 Robert H. Becker , David J. Helfand , Richard L. White , Deanne D. Proctor

The global contribution of unresolved gamma-ray point sources to the extragalactic gamma-ray background has been recently measured down to gamma-ray fluxes lower than those reached with standard source detection techniques, and by employing…

高能天体物理现象 · 物理学 2020-05-27 Silvia Manconi , Michael Korsmeier , Fiorenza Donato , Nicolao Fornengo , Marco Regis , Hannes Zechlin

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…

天体物理学 · 物理学 2009-11-07 Caleb A. Scharf , Reshmi Mukherjee

The unidentified EGRET source 3EG J1828+0142, located at (l,b) ~ (31.9,5.8) (Hartman et al. 1999), is particularly enigmatic since it displays very high variability over timescales of months (Torres et al. 2000, Tompkins 1999) yet no blazar…

EGRET can now study six pulsars since the recent detection of PSR B1951+32. Careful analysis of the three brightest pulsars shows that gamma rays are emitted through essentially the entire rotation. This calls into question the previous…

天体物理学 · 物理学 2011-04-15 P. L. Nolan , the EGRET team

The GALPROP model for cosmic-ray propagation is able to make explicit predictions for the distribution of galactic diffuse gamma-rays. We compare different propagation models with gamma-ray spectra measured by EGRET for various regions of…

天体物理学 · 物理学 2009-11-11 Andrew W. Strong , Igor V. Moskalenko , Olaf Reimer

The EGRET experiment aboard the Compton Gamma-Ray Observatory (CGRO) has observed at energies above 100 MeV strong gamma-ray flares with short-term time variability from the gamma-ray blazars 3C 279 and PKS 1622-297. During these flaring…

Blazars represent dominant population of the extragalactic $\gamma$-ray sources in the Universe. These sources exhibit some characteristic properties like strong and non-thermal continuum emission over the entire electromagnetic spectrum…

高能天体物理现象 · 物理学 2020-10-07 K. K. Singh , P. J. Meintjes

We search for the long-term variability of the \gamma-ray sky in the energy range E > 1 GeV with 168 weeks of Fermi-LAT data. We perform a full sky blind search for regions with variable flux looking for deviations from uniformity. We bin…

高能天体物理现象 · 物理学 2015-06-03 M. S. Pshirkov , G. I. Rubtsov

The AGILE gamma-ray satellite provides large sky exposure levels ($\geq 10^9$ cm$^2$ s per year on the Galactic Plane) with sensitivity peaking at $E\sim$100 MeV where the bulk of pulsar energy output is typically released. Its $\sim$1…

高能天体物理现象 · 物理学 2019-08-14 Maura Pilia , Alberto Pellizzoni

The limited angular resolution of gamma-ray telescopes prevents the straight identification of the majority of the sources detected so far. While the only certified galactic gamma-ray emitters are associated with pulsars, more than 90% of…

We suggest that ultraluminous X-ray sources (ULXs) and some of the variable low latitude EGRET gamma-ray sources may be two different manifestations of the same underlying phenomena: high-mass microquasars with relativistic jets forming a…

天体物理学 · 物理学 2007-05-23 Yousaf M. Butt , Gustavo E. Romero , Diego F. Torres

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…

天体物理学 · 物理学 2011-04-15 Yu. A. Golubkov , M. Yu. Khlopov

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters'') is isotropic. We study both…

天体物理学 · 物理学 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

Blazars, a subset of powerful active galactic nuclei, feature relativistic jets that shine in a broadband electromagnetic radiation, e. g. from radio to TeV emission. Here I present the results of the studies that explore gamma-ray and…

高能天体物理现象 · 物理学 2022-10-18 Gopal Bhatta