General Relativistic Effects on Neutrino‐driven Winds from Young, Hot Neutron Stars and<i>r</i>‐Process Nucleosynthesis

Abstract

Neutrino-driven wind from young hot neutron star, which is formed by\nsupernova explosion, is the most promising candidate site for r-process\nnucleosynthesis. We study general relativistic effects on this wind in\nSchwarzschild geometry in order to look for suitable conditions for a\nsuccessful r-process nucleosynthesis. It is quantitatively discussed that the\ngeneral relativistic effects play a significant role in increasing entropy and\ndecreasing dynamic time scale of the neutrino-driven wind. Exploring wide\nparameter region which determines the expansion dynamics of the wind, we find\ninteresting physical conditions which lead to successful r-process\nnucleosynthesis. The conditions which we found realize in the neutrino-driven\nwind with very short dynamic time scale $\\tau_{\\rm dyn} \\sim 6$ ms and\nrelatively low entropy $S \\sim 140$. We carry out the $\\alpha$-process and\nr-process nucleosynthesis calculation on these conditions by the use of our\nsingle network code including over 3000 isotopes, and confirm quantitatively\nthat the second and third r-process abundance peaks are produced in the\nneutrino-driven wind.\n