nu-Process Nucleosynthesis in Population III Core-Collapse Supernovae

TL;DR

This study explores how neutrino interactions during Population III supernovae influence the creation of iron-peak elements, aligning models with observed elemental ratios in ancient stars.

Contribution

It demonstrates the significant role of the nu-process in producing odd-Z iron-peak elements and matches supernova models with observed stellar abundance ratios.

Findings

Nu-process enhances Sc, Mn, Co production in supernova ejecta.

Models with specific neutrino energies reproduce observed Mn/Fe ratios.

Additional processes are needed to fully explain Sc/Fe and Co/Fe ratios.

Abstract

We investigate the effects of neutrino-nucleus interactions (the nu-process) on the production of iron-peak elements in Population III core-collapse supernovae. The nu-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_sol and 25 M_sol stars with the nu-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 x 10^{53} 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 nu-process.