Nuclei in central engine of core-collapse supernovae

Abstract

This article summarizes recent works by the author (Furusawa, 2013, Astrophys. J. 772, 95, Nagakura 2017, The Astrophysical Journal Supplement Series 229, 42, Furusawa, 2018, Phys. Rev. C 98, 065802, Furusawa, 2020, Progress of Theoretical and Experimental Physics 2020, 013D05) and presents a short review on equations of state (EOSs) based on the extended nuclear statistical equilibrium (NSE) and which nuclei appear in numerical simulations for central engines of core collapse supernovae. NSE EOSs as well as the weak interactions of nucleons and nuclei have great impacts on the results of supernova simulations. Before the core-bounce, heavy nuclei are dominant at the center of collapsing cores and their weak interactions greatly affect the neutrino observations and following dynamics of the core. After the core-bounce, heavy nuclei are dissolved to nucleons and light clusters between the expanding shock wave and the new-born neutron star. The neutrino interaction of nucleons and of light clusters is one of the most important ingredients to determine the shock-wave dynamics and supernova explosion of the outer envelopes. To understand the mechanism and to predict neutrino observations of core collapse supernovae, we require further investigations of in-medium effects on the free energies and weak interaction rates for light and heavy nuclei. The primary targets of core-collapse nuclei are medium-mass, neutron-rich nuclei with proton numbers 25–45 and neutron numbers 40–85, whereas deuterons and alpha particles would have important roles in the shock revival phase.