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Related papers: Components of the Extragalactic Gamma Ray Backgrou…

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The extragalactic background (EGB) of diffuse gamma rays can be determined by subtracting the Galactic contribution from the data. This requires a Galactic model (GM) and we include for the first time the contribution of dark matter…

Astrophysics · Physics 2009-11-13 W. de Boer , A. Nordt , C. Sander , V. Zhukov

We study the origin of the extragalactic diffuse gamma-ray background using the data from the Fermi telescope. To estimate the background level, we count photons at high Galactic latitudes |b|>60 degrees. Subtracting photons associated to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 A. Neronov , D. V. Semikoz

The Extragalactic Background Light (EBL) from the infrared (IR) through the ultraviolet (UV) is dominated by emission from stars, either directly or through absorption and reradiation by dust. It can thus give information on the star…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Justin D. Finke

One way to understand the nonthermal history of the universe is by establishing the origins of the unresolved and truly diffuse extragalactic gamma rays. Dim blazars and radio/gamma galaxies certainly make an important contribution to the…

Astrophysics · Physics 2009-06-23 Charles D. Dermer

We describe the properties of the blazars detected by EGRET and summarize the results on the calculations of the evolution and luminosity function of these sources. Of the large number of possible origins of extragalactic diffuse gamma-ray…

Astrophysics · Physics 2009-10-31 R. Mukherjee , J. Chiang

Several classes of astrophysical sources contribute to the approximately isotropic gamma-ray background measured by the Fermi Gamma-Ray Space Telescope. In this paper, we use Fermi's catalog of gamma-ray sources (along with corresponding…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Ilias Cholis , Dan Hooper , Samuel D. McDermott

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

Galaxies experiencing intense star-formation episodes are expected to be rich in energetic cosmic rays (CRs). These CRs undergo hadronic interactions with the interstellar gases of their host to drive $\gamma$-ray emission, which has…

High Energy Astrophysical Phenomena · Physics 2021-06-18 Ellis R. Owen , Khee-Gan Lee , Albert K. H. Kong

The extragalactic background light (EBL) is one of the fundamental observational quantities in cosmology. All energy releases from resolved and unresolved extragalactic sources, and the light from any truly diffuse background, excluding the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Eli Dwek , Frank Krennrich

Despite the influx of unprecedented-quality data from the Fermi Gamma-Ray Space Telescope that have been collected over nine years of operation, the contribution of normal star-forming galaxies to the extragalactic gamma-ray background…

High Energy Astrophysical Phenomena · Physics 2018-12-19 I. Komis , V. Pavlidou , A. Zezas

The gamma-ray background is still a subject under great debate. All phenomena in the universe emitting gamma-rays can contribute directly as diffuse emission or as an isotropic component from unresolved point sources. The question of the…

Astrophysics · Physics 2007-11-29 Tanja M. Kneiske

The COMPTEL and EGRET detectors aboard the Compton Gamma-Ray Observatory measured an extragalactic gamma-ray background extending from MeV energies up to about 100 GeV. Calculations performed making reasonable assumptions indicate that…

Astrophysics · Physics 2009-11-06 F. W. Stecker , M. H. Salamon

The origin of the Isotropic Diffuse $\gamma$-Ray Background (IGRB) is one of the most intriguing mystery in astrophysics. Recently the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has measured the IGRB spectrum…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Mattia Di Mauro

The extragalactic $\gamma$-ray background (EGB) arises from the accumulation of $\gamma$-ray emissions from resolved and unresolved extragalactic sources as well as diffuse processes. It is important to study the statistical properties of…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Masato Shirasaki , Oscar Macias , Shunsaku Horiuchi , Naoki Yoshida , Chien-Hsiu Lee , Atsushi J. Nishizawa

We present the first interpretation of the new isotropic diffuse gamma-ray background (IGRB), measured by the Fermi Large Area Telescope (LAT), based on a statistical analysis. We demonstrate that the gamma-ray emission from unresolved…

High Energy Astrophysical Phenomena · Physics 2015-02-11 Mattia Di Mauro

Recent observations of blazars at high energy (HE, 0.1-100 GeV) and very high energy (VHE, >0.1 TeV) have provided important constraints on the intensity and spectrum of the diffuse Extragalactic Background Light (EBL), shedding light on…

High Energy Astrophysical Phenomena · Physics 2013-09-04 Luigi Costamante

(Abridged) We present a new model of the blazar gamma-ray luminosity function (GLF) and the spectrum of the extragalactic gamma-ray background (EGRB), which is consistent with the observed distributions of EGRET blazars. The unified…

Astrophysics · Physics 2011-01-27 Yoshiyuki Inoue , Tomonori Totani

We present a new assessment of the contribution of Blazars to the extragalactic background radiation across the e.m. spectrum. Our calculations rely on deep Blazar radio counts that we derived combining several multifrequency surveys. The…

Astrophysics · Physics 2009-11-13 P. Giommi , S. Colafrancesco , E. Cavazzuti , M. Perri , C. Pittori

We discuss the contribution of the blazar population to the extragalactic background radiation across the electromagnetic (e.m.) spectrum with particular reference to the microwave, hard-X-ray and gamma-ray bands. Our estimates are based on…

Astrophysics · Physics 2007-05-23 P. Giommi , S. Colafrancesco

The latest determination of the extragalactic gamma-ray background (EGRB) radiation by Fermi is compared with the theoretical prediction of the blazar component by Inoue & Totani (2009; hereafter IT09). The Fermi EGRB spectrum is in…

High Energy Astrophysical Phenomena · Physics 2010-01-05 Yoshiyuki Inoue , Tomonori Totani , Susumu Inoue , Masakazu A. R. Kobayashi , Jun Kataoka , Rie Sato