Did cosmic rays reionize the intergalactic medium?

Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/4439

Title:	Did cosmic rays reionize the intergalactic medium?
Authors:	Nath, Biman B. Biermann, P.L.
Issue Date:	1993
Publisher:	Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 1993, Vol.2651, p241
Abstract:	We investigate the role of cosmic rays from young galaxies in heating and ionizing the intergalactic medium (IGM) at high redshift. Using the IRAS observations at 60 microns, we estimate the cosmic ray luminosity density at the present epoch. We consider various forms of luminosity evolution in redshift, and calculate (i) the thresholds corresponding to the upper limits of Gunn-Peterson optical depth, (ii) the Compton γ-parameter for an IGM heated by cosmic rays (and compare it with the upper limits from COBE measurements), and (iii) an estimated limit from the integral of metal enrichment. We show that certain models, with rather strong evolution and early formation of galaxies, allow reionization of the IGM, consistent with all known constraints.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/4439
ISSN:	0035-8711 1365-2966 (Online)
Alternative Location:	http://adsabs.harvard.edu/abs/1993MNRAS.265..241N http://arxiv.org/abs/astro-ph/9306001
Copyright:	1993 Royal Astronomical Society
Appears in Collections:	Research Papers (A&A)

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