Related papers: Gamma-Ray Absorption at High Redshifts and the Gam…
We calculate the absorption of 10-500 GeV gamma-rays at high redshifts. This calculation requires the determination of the high-redshift evolution of the intergalactic starlight photon field, including its IR-UV spectral energy…
The pair-production absorption of high-energy gamma-rays by intergalactic low-energy photons is expected to produce a high-energy cutoff in the spectra of extragalactic sources which is a sensitive function of redshift. We first discuss the…
We present a new calculation of the intergalactic gamma-ray absorption coefficient as a function of both energy and redshift. In reexamining this problem, we make use of a new, empirically based calculation (as opposed to previous model…
We extend earlier calculations of the attenuation suffered by gamma rays during their propagation from extragalactic sources, obtaining new extinction curves for gamma rays down to 10 GeV in energy, from sources up to a redshift of z=3.
The case of gamma-ray absorption due to photon-photon pair production of jet photons in the external photon environment like accretion disk and broad-line region radiation field of gamma-ray loud active galactic nuclei (AGN) that exhibit…
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.…
Adopting a recent calculation of the Galactic interstellar radiation field, we calculate the attenuation of the very high energy gamma rays from the Galactic sources. The infra-red radiation background near the Galactic Center is very…
The next generation of gamma-ray telescopes may be able to observe gamma-ray blazars at high redshift, possibly out to the epoch of reionization. The spectrum of such sources should exhibit an absorption edge due to pair-production against…
Blazars with redshifts z<0.1 are likely candidates for detection at energies in the range 300 GeV - 50 TeV with Cerenkov telescopes and scintillator arrays. We present gamma-ray flux predictions for a sample of 15 nearby flat-spectrum radio…
High-energy photons emitted from gamma-ray bursts (GRBs) are subject to pair-production interactions with lower energy photons, leading to an effective optical depth. In this Letter, we estimate the opacity resulting from photon fields…
Following our previously proposed technique, we have used the recent gamma-ray observations of Mrk 421 to place theoretically significant constraints on and possible estimates of the intergalactic infrared radiation field (IIRF) which are…
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.…
We derive a new and user friendly simple analytic approximation for determining the effect of intergalactic absorption in the energy range 0.2-2 TeV and the redshift range 0.05-0.4. In these ranges, the form of the absorption coeeficient is…
We present two models for the cosmological UV background light, and calculate the opacity of GeV gamma--rays out to redshift 9. The contributors to the background include 2 possible quasar emissivities, and output from star--forming…
We present a new calculation of the intergalactic $\gamma$-ray pair-production absorption coefficient as a function of both energy and redshift up to the redshift of 3C279, z = 0.54. In reexamining this problem, we make use of new…
The question of a possible redshift-dependence of gamma-ray absorption due to gamma-gamma pair production of jet photons in the accretion disk and BLR radiation field in strong-line quasars is investigated. For this relevant aspects of…
This paper presents an analysis of the dependence of the opacity for high-energy gamma-rays to gamma-gamma absorption by low-energy photons, on the polarization of the gamma-ray and target photons. This process has so far only been…
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…
Galactic Gamma ray astronomy at very high energy (E > 30 TeV) is a vital tool in the study of the non-thermal universe. The interpretation of the observations in this energy region requires the precise modeling of the attenuation of photons…
Gamma rays with energy above 10 GeV interact with optical-UV photons resulting in pair production. Therefore, a large sample of high redshift sources of these gamma rays can be used to probe the extragalactic background starlight (EBL) by…