Ionization and supernova feedback from the first stars

The first light in the Universe is given by the first-generation metal-free (Pop III) stars. It modifies the density distribution of the cosmic structures, and affects the efficiency of metal enrichment. The elemental abundances of Pop III stars are considered to be inherited by the nearby extremely metal-poor (EMP) stars. To investigate the dominant enrichment process and ionization efficiency of Pop III stars, we carry out a series of numerical simulations including the feedback effects of photoionization and supernovae (SNe) of Pop III stars with a range of masses of minihaloes (MHs), Mhalo, and Pop III stars, MPopIII, and compare with the metallicity range and elemental abundances of observed EMP stars. We find that the metal-rich ejecta reaches neighboring haloes, and external enrichment (EE) occurs when the ionization front expands for pair-instability SN (PISN) cases. The neighboring haloes are only superficially enriched, and the metallicity of theclouds is Z