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Related papers: Extragalactic Background Light and Gamma-Ray Atten…

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The Extragalactic Background Light (EBL) stands for the mean surface brightness of the sky as we would see it from a representative vantage point in the intergalactic space outside of our Milky Way Galaxy. Averaged over the whole 4 pi solid…

Astrophysics of Galaxies · Physics 2019-05-23 Kalevi Mattila , Petri Väisänen

Ground-based observatories have been collecting 0.2 - 20 TeV gamma rays from blazars for about twenty years. These gamma rays can experience absorption along the line of sight due to interactions with the extragalactic background light…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-14 Jonathan Biteau , David A. Williams

Gamma-ray telescopes have reported some surprising observations of multi-TeV photons from distant active galactic nuclei (AGN), which show no significant attenuation due to pair production on either the extragalactic background light (EBL),…

High Energy Astrophysical Phenomena · Physics 2010-02-23 Warren Essey , Alexander Kusenko

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

The unexpectedly hard spectra measured by HESS for the BLLacs 1ES 1101-232 and H 2356-309 has allowed an upper limit on the Extragalactic Background Light (EBL) to be derived in the optical/near-infrared range, which is very close to the…

Astrophysics · Physics 2008-11-26 L. Costamante

The extragalactic background light (EBL) is of fundamental importance both for understanding the entire process of galaxy evolution and for gamma-ray astronomy. However, the overall spectrum of the EBL between 0.1 and 1000 microns has never…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Alberto Domínguez

We consider the ensemble of very-high-energy gamma-ray sources observed at distances and energies where a significant absorption of gamma rays is expected due to pair production on the extragalactic background light (EBL). Previous studies…

High Energy Astrophysical Phenomena · Physics 2019-12-04 Alexander Korochkin , Grigory Rubtsov , Sergey Troitsky

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

Gamma-rays propagating through space are likely to be extinguished via electron-positron pair production off of the ambient extragalactic background light (EBL). The spectrum of the EBL is produced by starlight (and starlight reprocessed by…

High Energy Astrophysical Phenomena · Physics 2013-12-11 Rebecca Reesman , T. P. Walker

This review covers the measurements related to the extragalactic background light (EBL) intensity from gamma-rays to radio in the electromagnetic spectrum over 20 decades in the wavelength. The cosmic microwave background (CMB) remains the…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-11 Asantha Cooray

The extragalactic background light (EBL) is the cumulative radiation outside the Milky Way. The determination of its corresponding primary emitting sources as well as its total energy level across the entire electromagnetic spectrum has…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-27 Qi-Ning Hsu , L. L. Cowie , Chian-Chou Chen , A. J. Barger

The extragalactic background light (EBL) is the second-most-intense form of cosmic background light (the first being the cosmic microwave background) and contains the redshifted optical radiation, from infra-red to ultraviolet, emitted…

High Energy Astrophysical Phenomena · Physics 2019-09-02 Stephan O'Brien

We present new synthesis models of the extragalactic background light (EBL) from far infra-red (FIR) to TeV gamma-rays, with an emphasis on the extreme ultraviolet (UV) background which is responsible for the observed ionization and thermal…

Astrophysics of Galaxies · Physics 2019-02-20 Vikram Khaire , Raghunathan Srianand

The flux of high-energy astrophysical $\gamma$ rays is attenuated by the production of electron-positron pairs from scattering off of extragalactic background light (EBL). We use the most up-to-date information on galaxy populations to…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-25 José Luis Bernal , Andrea Caputo , Gabriela Sato-Polito , Jordan Mirocha , Marc Kamionkowski

Motivated by the discovery of the ultra-strong emission line starburst galaxies (EELGs) known as "green pea galaxies", we consider here their contribution to the intergalactic flux of ionizing UV at high redshifts. Most galaxies that have…

Astrophysics of Galaxies · Physics 2021-08-19 Matthew A. Malkan , Sean T. Scully , Floyd W. Stecker

In this chapter, we discuss the contributions of gamma-ray astronomy at TeV energies to our understanding of the visible content and structure of the universe. We start from the present epoch with the second most intense electromagnetic…

High Energy Astrophysical Phenomena · Physics 2021-12-14 Elisa Pueschel , Jonathan Biteau

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 extragalactic background light (EBL) from the far infrared through the visible and extending into the ultraviolet is thought to be dominated by starlight, either through direct emission or through absorption and reradiation by dust.…

High Energy Astrophysical Phenomena · Physics 2010-03-04 Justin D. Finke , Soebur Razzaque , Charles D. Dermer

The Extragalactic Background Light (EBL) as an integrated light from outside of our Galaxy includes information of the early universe and the Dark Ages. We analyzed the spectral data of the astrophysical diffuse emission obtained with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Kohji Tsumura , Toshio Matsumoto , Shuji Matsuura , Itsuki Sakon , Takehiko Wada

Astrophysical sources outside the Milky Way, such as active galactic nuclei and star-forming galaxies, leave their imprint on the gamma-ray sky as nearly isotropic emission referred to as the Extragalactic Gamma-Ray Background (EGB). While…

High Energy Astrophysical Phenomena · Physics 2017-01-12 Mariangela Lisanti , Siddharth Mishra-Sharma , Lina Necib , Benjamin R. Safdi