Dependence of r-process Yields on the Progenitor Masses of Type II Supernovae

Abstract.

The r-process in Type II supernovae has been examined using a semianalytic, general relativistic model of neutrino winds and a nuclear reaction network code. We found that the relatively high entropy ( $\sim 140N_{A}k$) was obtained for the model of a massive proto-neutron star ($\sim 2M_\odot$). Furthermore, the dynamical timescale of the wind was significantly short ($\sim$ 0.01 s) for the model of a high neutrino luminosity ($\sim 10^{52}$ ergs s^-1). These results imply that massive Type II supernovae are the site of r-process and the early times of the neutrino wind phases mainly contribute to its nucleosynthesis.