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arXiv · 0903.2045

Ionizing radiation from z=4-10 galaxies

Alexei O. Razoumov·Jesper Sommer-Larsen
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Abstract

We compute the escape of ionizing radiation from galaxies in the redshift interval z=4-10, i.e., during and after the epoch of reionization, using a high-resolution set of galaxies, formed in fully cosmological simulations. The simulations invoke early, energetic feedback, and the galaxies evolve into a realistic population at z=0. Our galaxies cover nearly four orders of magnitude in masses (10^{7.8}-10^{11.5}\msun) and more than five orders in star formation rates (10^{-3.5}-10^{1.7}\msun\yr^{-1}), and we include an approximate treatment of dust absorption. We show that the source-averaged Lyman-limit escape fraction at z=10.4 is close to 80% declining monotonically with time as more massive objects build up at lower redshifts. Although the amount of dust absorption is uncertain to 1-1.5 dex, it is tightly correlated with metallicity; we find that dust is unlikely to significantly impact the observed UV output. These results support reionization by stellar radiation from low-luminosity dwarf galaxies and are also compatible with Lyman continuum observations and theoretical predictions at z\sim3-4.

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Alexei O. Razoumov, Jesper Sommer-Larsen. 2010-01-21. Ionizing radiation from z=4-10 galaxies. https://doi.org/10.1088/0004-637x%2F710%2F2%2F1239

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