2006/05/20 by Akio K. Inoue, Ikuru Iwata, Jean-Michel Deharveng · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1111/j.1745-3933.2006.00195.x
published as Mon.Not.Roy.Astron.Soc.Lett. 371 (2006) L1-L5 · MNRAS Letters, in press
arxiv created 2006/05/20 · arxiv updated 2009/12/01
The escape fraction of ionizing photons from galaxies is a crucial quantity controlling the cosmic ionizing background radiation and the reionization. Various estimates of this parameter can be obtained in the redshift range, z=0--6, either from direct observations or from the observed ionizing background intensities. We compare them homogeneously in terms of the observed flux density ratio of ionizing (∼900 Årest-frame) to non-ionizing ultraviolet (∼1500 Årest-frame) corrected for the intergalactic absorption. The escape fraction is found to increase by an order of magnitude, from a value less than 0.01 at z\la1 to about 0.1 at z\ga4.