Year: 1993
Type: article
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 μm, 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 y-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.
Authors: B. B. Nath, P. L. Biermann
Institution: Max Planck Institute for Radio Astronomy
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2012498678