COSMIC REIONIZATION ON COMPUTERS: THE FAINT END OF THE GALAXY LUMINOSITY FUNCTION

摘要

Using numerical cosmological simulations completed under the "Cosmic Reionization On Computers" project, I explore theoretical predictions for the faint end of the galaxy UV luminosity functions at z greater than or similar to 6. A commonly used Schechter function approximation with the magnitude cut at M-cut similar to -13 provides a reasonable fit to the actual luminosity function of simulated galaxies. When the Schechter functional form is forced on the luminosity functions from the simulations, the magnitude cut Mcut is found to vary between -12 and -14 with a mild redshift dependence. An analytical model of reionization from Madau et al., as used by Robertson et al., provides a good description of the simulated results, which can be improved even further by adding two physically motivated modifications to the original Madau et al. equation.