General Relativistic Effects on Neutrino‐driven Winds from Young, Hot Neutron Stars andr‐Process Nucleosynthesis

Neutrino-driven winds from young hot neutron stars, which are formed by supernova explosions, are the most promising candidate site for r -process nucleosynthesis. We study general relativistic effects on this wind in Schwarzschild geometry in order to look for suitable conditions for successful r -process nucleosynthesis. It is quantitatively demonstrated that general relativistic effects play a significant role in increasing the entropy and decreasing the dynamic timescale of the neutrino-driven wind. Exploring the wide parameter region that determines the expansion dynamics of the wind, we find interesting physical conditions that lead to successful r -process nucleosynthesis. The conditions that we found are realized in a neutrino-driven wind with a very short dynamic timescale, τ dyn ~ 6 ms, and a relatively low entropy, S ~ 140. We carry out α-process and r -process nucleosynthesis calculations on these conditions with our single network code, which includes over 3000 isotopes, and confirm quantitatively that the second and third r -process abundance peaks are produced in neutrino-driven winds.