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We present here the extragalactic background light (EBL) predicted by semi-analytic models of galaxy formation, and show how measurements of the absorption of gamma rays of $\sim$ TeV energies via pair production on the EBL can probe…

Astrophysics · Physics 2008-11-26 Joel R. Primack , James S. Bullock , Rachel S. Somerville , Donn MacMinn

We discuss how measurements of the absorption of $\gamma$-rays from GeV to TeV energies via pair production on the extragalactic background light (EBL) can probe important issues in galaxy formation. We use semi-analytic models (SAMs) of…

I discuss how measurements of the absorption of $\gamma$-rays from GeV to TeV energies via pair production on the extragalactic background light (EBL) can probe important issues in galaxy formation. We use semi-analytic models (SAMs) of…

Astrophysics · Physics 2007-05-23 Joel R. Primack

We discuss how measurements of the absorption of gamma-rays from GeV to TeV energies via pair production on the extragalactic background light (EBL) can probe important issues in galaxy formation. Semi-analytic models (SAMs) of galaxy…

Astrophysics · Physics 2009-11-10 Joel R. Primack , James S. Bullock , Rachel S. Somerville

Gamma rays of ~TeV energies from distant sources suffer attenuation due to pair production off of ~1 micron EBL photons. We may exploit this process in order to indirectly measure the EBL and constrain models of galaxy formation. Here,…

Astrophysics · Physics 2010-12-09 J. S. Bullock , R. S. Somerville , D. MacMinn , J. R. Primack

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 present models of the extragalactic background light (EBL) based on several scenarios of galaxy formation and evolution. We have treated galaxy formation with the Press-Schecter approximation for both cold dark matter (CDM) and cold+hot…

Astrophysics · Physics 2009-12-10 D. MacMinn , J. R. Primack

We present models of the extragalactic background light (EBL) based on several scenarios of galaxy formation and evolution. We have treated galaxy formation with the Press-Schecter approximation for both cold dark matter (CDM) and cold+hot…

Astrophysics · Physics 2008-02-03 Donn MacMinn , Joel R. Primack

We discuss the problem of the absorption of very high-energy gamma-rays by pair production interactions with extragalactic photons which originate from stellar emission in the near IR-UV and reradiation of starlight in the mid- and far-IR.…

Astrophysics · Physics 2007-05-23 F. W. Stecker , O. C. De Jager

In this paper, I will take a synoptic approach to determining the intergalactic infrared radiation field (IIRF). This approach draws on both the multi-TeV gamma-ray observations and the infrared background observations and relates them via…

Astrophysics · Physics 2007-05-23 F. W. Stecker

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

The development of techniques whereby gamma rays of energy 100 GeV and above can be studied from the ground, using indirect, but sensitive, techniques has opened up a new area of high energy photon astronomy. The most exciting result that…

Astrophysics · Physics 2009-11-10 D. Horan , T. C. Weekes

An important contribution to the gamma-ray emission of our Galaxy is the Galactic Diffuse emission. We present specific developments within the PICARD code for modeling of Galactic cosmic ray propagation that are relevant for the…

High Energy Astrophysical Phenomena · Physics 2017-01-26 Felix Niederwanger , Olaf Reimer , Ralf Kissmann , Richard Tuffs

TeV gamma rays from distant astrophysical sources are attenuated due to electron-positron pair creation by interacting with ultraviolet/optical to infrared photons which fill the universe and are collectively known as the extra-galactic…

Astrophysics · Physics 2014-11-18 Soebur Razzaque , Charles D. Dermer , Justin D. Finke

Recent observations have shown that pulsars are surrounded by extended regions which emit TeV-scale gamma rays through the inverse Compton scattering of very high energy electrons and positrons. Such TeV halos are responsible for a large…

High Energy Astrophysical Phenomena · Physics 2022-07-20 Fei Xu , Dan Hooper

Ultrahigh energy protons and nuclei from extragalactic cosmic ray sources initiate intergalactic electromagnetic cascades, resulting in observable fluxes of $\gamma$-rays in the GeV-TeV energy domain. The total spectrum of such cascade…

High Energy Astrophysical Phenomena · Physics 2021-07-21 E. V. Khalikov , T. A. Dzhatdoev

We present new calculations of the evolving UV background out to the epoch of cosmological reionization and make predictions for the amount of GeV gamma-ray attenuation by electron-positron pair production. Our results are based on recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Rudy C. Gilmore , Piero Madau , Joel R. Primack , Rachel S. Somerville , Francesco Haardt

The survey of the inner Galaxy with H.E.S.S. was remarkably successful in detecting a wide range of new very-high-energy gamma-ray sources. New TeV gamma-ray emitting source classes were established, although several of the sources remain…

Astrophysics of Galaxies · Physics 2015-05-13 S. Funk , J. A. Hinton , G. Hermann , S. Digel

A Galactic cosmic-ray transport model featuring non-homogeneous transport has been developed over the latest years. This setup is aimed at reproducing gamma-ray observations in different regions of the Galaxy (with particular focus on the…

High Energy Astrophysical Phenomena · Physics 2022-10-18 Pedro De la Torre Luque , Daniele Gaggero , Dario Grasso

The energy spectra of TeV gamma-rays from blazars, after being corrected for intergalatic absorption in the Extragalactic Background Light (EBL), appear unusually hard, a fact that poses challenges to the conventional models of particle…

Astrophysics · Physics 2009-11-13 F. Aharonian , D. Khangulyan , L. Costamante
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