English

TeV Gamma-Ray Absorption and the Intergalactic Infrared Background

Astrophysics 2007-05-23 v2

Abstract

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 the semi-empirical modelling method of Malkan and Stecker. I discuss the evidence for an intergalactic infrared background obtained by an analysis of the HEGRA observations of the high energy gamma-ray spectrum of Mrk 501 and from constraints from Mrk 421 deduced from the Whipple air Cherenkov telescope results. I will show that this evidence is in accord with the predictions made by Malkan and Stecker for the intergalactic infrared spectral energy distribution produced by galaxies. The Malkan-Stecker predictions are also in excellent agreement with mid- and far infrared galaxy counts. However, there may be potential problems relating these predictions with the results of the analysis of COBE-DIRBE far infrared data. The gamma-ray and COBE-DIRBE observations may also need to be reconciled. I will discuss possible ways to resolve this situation including a partial nullification of the γ\gamma-ray absorption process which can hypothetically occur if Lorentz invariance is broken.

Keywords

Cite

@article{arxiv.astro-ph/0010015,
  title  = {TeV Gamma-Ray Absorption and the Intergalactic Infrared Background},
  author = {F. W. Stecker},
  journal= {arXiv preprint arXiv:astro-ph/0010015},
  year   = {2007}
}

Comments

15 latex pages with 5 eps figures and newpasp style file included, Invited Paper for Proc. IAU Symp. 204 "The Extragalactic Background and its Cosmological Implications", M. Harwit and M.G. Hauser, eds., Corrected FIG. 1

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