Nucleosynthesis in the Innermost Ejecta of Neutrino-driven Supernova Explosions in Two Dimensions

We examine nucleosynthesis in the innermost neutrino-processed ejecta (a few 10(3)M circle dot) of self-consistent two-dimensional explosion models of core-collapse supernovae (CCSNe) for six progenitor stars with different initial masses. Three models have initial masses near the low-mass end of the SN range of 8.8 M circle dot(e8.8; electron-capture SN), 9.6 M circle dot(z9.6), and 8.1 M circle dot(u8.1), with initial metallicities of 1, 0, and 10(-4)times the solar metallicity, respectively. The other three are solar-metallicity models with initial masses of 11.2 M(s11), 15M circle dot(s15), and 27 M circle dot(s27). The low-mass models e8.8, z9.6, and u8.1 exhibit high production factors (nucleosynthetic abundances relative to the solar abundances) of 100-200 for light trans-Fe elements from Zn to Zr. This is associated with an appreciable ejection of neutron-rich matter in these models. Remarkably, the nucleosynthetic outcomes for the progenitors e8.8 and z9.6 are almost identical, including interesting productions of Ca-48 and Fe-60, irrespective of their quite different (O-Ne-Mg and Fe) cores prior to collapse. In the more massive models sll, sl5, and s27, several proton-rich isotopes of light trans-Fe elements including the p-isotope Mo (for s27) are made, up to production factors of similar to 30. Both electron-capture SNe and CCSNe near the low-mass end can therefore be dominant contributors to the Galactic inventory of light trans-Fe elements from Zn to Zr and probably Ca and live Fe-60. The innermost ejecta of more massive SNe may have only subdominant contributions to the chemical enrichment of the Galaxy except for Mo-92.