Gamma-Rays from Large Scale Structure Formation and the Warm-Hot Intergalactic Medium: Cosmic Baryometry with Gamma-Rays
Abstract
It is shown that inverse Compton gamma-rays from electrons accelerated in large scale structure formation shocks can be crucially affected by non-gravitational effects such as radiative cooling and galaxy formation, with corresponding uncertainties by an order of magnitude in either the gamma-ray source counts or the extragalactic background contribution. However, this also implies that such gamma-rays may in the near future provide us with valuable information about the fraction of cosmic baryons in different forms, particularly the warm-hot intergalactic medium where the majority of the baryons in the universe are believed to reside. We address this problem in a simple way through semi-analytic modeling of structure formation shocks which self-consistently treats merger and accretion shocks.
Cite
@article{arxiv.astro-ph/0502338,
title = {Gamma-Rays from Large Scale Structure Formation and the Warm-Hot Intergalactic Medium: Cosmic Baryometry with Gamma-Rays},
author = {Susumu Inoue and Masahiro Nagashima},
journal= {arXiv preprint arXiv:astro-ph/0502338},
year = {2009}
}
Comments
7 pages, 2 figures; slightly modified version of article to appear in Proc. of the "International Symposium on High Energy Gamma-Ray Astronomy" Heidelberg (2004), eds. F.A. Aharonian, H.J. Voelk and D. Horns (AIP, NY)