Ν-process Nucleosynthesis in Population Iii Core-collapse Supernovae

We investigate the effects of neutrino-nucleus interactions (the ν-process) on the production of iron-peak elements in Population III core-collapse supernovae. The ν-process and the following proton and neutron capture reactions produce odd-Z iron-peak elements in complete and incomplete Si burning region. This reaction sequence enhances the abundances of Sc, Mn, and Co in the supernova ejecta. The supernova explosion models of 15 M⊙ and 25 M⊙ stars with the ν-process well reproduce the averaged Mn/Fe ratio observed in extremely metal-poor halo stars. In order to reproduce the observed Mn/Fe ratio, the total neutrino energy in the supernovae should be 3 − 9× 1053 ergs. Stronger neutrino irradiation and other production sites are necessary to reproduce the observed Sc/Fe and Co/Fe ratios, although these ratios increase by the ν-process. Subject headings: Galaxy: halo — neutrinos — nuclear reactions, nucleosynthesis, abundances — supernovae: general