English
Related papers

Related papers: The Cosmological Optical Convergence: Extragalacti…

200 papers

Axion-like particles (ALPs) provide a feasible explanation for the observed lower TeV opacity of the Universe. If the anomaly TeV transparency is caused by ALPs, then the fluxes of distant extragalactic sources will be enhanced at photon…

High Energy Astrophysical Phenomena · Physics 2021-11-17 Yun-Feng Liang , Xing-Fu Zhang , Ji-Gui Cheng , Hou-Dun Zeng , Yi-Zhong Fan , En-Wei Liang

The extragalactic background light (EBL) is comprised of the cumulative radiation from all galaxies and active galactic nuclei over the cosmic history. In addition to point sources, EBL also contains information from diffuse sources of…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-23 Yan Gong , Asantha Cooray , Ketron Mitchell-Wynne , Xuelei Chen , Michael Zemcov , Joseph Smidt

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

The vast majority of extragalactic sources detected in the very high energy (E> 100 GeV) domaine are active galactic nuclei (AGN) located at cosmological distances. During their travel towards Earth, the emitted gamma-rays suffer from…

High Energy Astrophysical Phenomena · Physics 2019-08-15 C. Romoli , D. A. Sanchez , M. Lorentz , P. Brun

We revisit the limits of the level of the extragalactic background light (EBL) recently reported by the MAGIC collaboration based on the observed gamma-ray spectrum of the quasar 3C279, considering the impact of absorption of high-energy…

Astrophysics · Physics 2009-11-13 F. Tavecchio , D. Mazin

Energy spectra of gamma-ray blazars may contain an imprint from the cosmic infrared background radiation due to gamma-ray absorption (pair-production) by soft photons constituting the extragalactic background light (EBL). The signature of…

Astrophysics · Physics 2009-09-29 F. Krennrich , E. Dwek

Attenuation of high-energy gamma rays by pair-production with UV, optical and IR extragalactic background light (EBL) photons provides a link between the history of galaxy formation and high-energy astrophysics. We present results from our…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 R. C. Gilmore , R. S. Somerville , J. R. Primack , A. Domínguez

Gamma-ray absorption due to gamma-gamma-pair creation on cosmological scales depends on the line-of-sight integral of the evolving density of low-energy photons in the Universe, i.e. on the history of the diffuse, isotropic radiation field.…

Astrophysics · Physics 2009-11-07 Tanja M. Kneiske , Karl Mannheim , Dieter H. Hartmann

We investigate potential $\gamma-\gamma$ absorption of gamma-ray emission from blazars arising from inhomogeneities along the line of sight, beyond the diffuse Extragalactic Background Light (EBL). As plausible sources of excess…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Anna Barnacka , Markus Bottcher , Iurii Sushch

We correct errors in Bernstein, Freedman & Madore (2002abc), a series of papers in which we described observations of the optical extragalactic background light (EBL). These errors pertain to the measurement of zodiacal light, given in the…

Astrophysics · Physics 2009-11-13 R. A. Bernstein , W. L. Freedman , B. F. Madore

Extragalactic Background Light (EBL) studies have revealed a significant discrepancy between direct measurements -- via instruments measuring "bare" sky from which Zodiacal and Galactic light models are subtracted -- and measurements of the…

We present a measurement of the absolute surface brightness of the zodiacal light (3900-5100A) toward a fixed extragalactic target at high ecliptic latitude based on moderate resolution (~1.3A per pixel) spectrophotometry obtained with the…

Astrophysics · Physics 2009-11-07 R. A. Bernstein , W. L. Freedman , B. F. Madore

The intrinsic flux of very high energy (VHE, Energy > 100 GeV) gamma-rays from extragalactic sources is attenuated due to pair production in the interaction with photons of the extragalactic background light (EBL). Depending on the distance…

High Energy Astrophysical Phenomena · Physics 2014-10-08 Manuel Meyer , Dieter Horns , Martin Raue

The origin of the extragalactic $\gamma$-ray background (EGB) has been debated for some time. { The EGB comprises the $\gamma$-ray emission from resolved and unresolved extragalactic sources, such as blazars, star-forming galaxies and radio…

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

TeV photons from blazars at relatively large distances, interacting with the optical-IR cosmic background, are efficiently converted into electron-positron pairs. The produced pairs are extremely relativistic (Lorentz factors of the order…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Tavecchio , G. Ghisellini , L. Foschini , G. Bonnoli , G. Ghirlanda , P. Coppi

The BL Lac object H1426+428 ($z\equiv 0.129$) is an established source of TeV $\gamma$-rays and detections of these photons from this object also have important implications for estimating the Extragalactic Background Light (EBL) in…

Several fluctuation studies on the near-infrared extragalactic background light (EBL) find an excess power at tens of arcminute scales ($\ell\sim10^3$). Emission from the intra-halo light (IHL) has been proposed as a possible explanation…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-07 Yun-Ting Cheng , James J. Bock

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

We present a semi-empirical model for the evolving far-infrared to ultraviolet diffuse background produced by stars in galaxies. The model is designed to reproduce the results of deep galaxy surveys, and therefore may be considered as a…

Astrophysics · Physics 2009-10-31 T. M. Kneiske , K. Mannheim , D. Hartmann