Experimental Challenge to Heavy Element Synthesis under Explosive Burning on Neutron Stars

¹ RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
² Center for Nuclear Study, the University of Tokyo, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan

^* Corresponding author: kubono@riken.jp

Published online: 14 January 2020

Abstract

Binary stellar systems that involve a neutron star or two neutron stars make interesting phenomena, X-ray bursts and kilo-novae, respectively, which involve explosive burning either in the proton-rich environment or in the neutron-rich environment. These are very important problems for nuclear astrophysics. First, the current effort for the explosive hydrogen burning, the rapid proton capture (rp) process which would take place on a neutron star surface in X-ray burst is discussed together with a new X-ray observation that suggests the rp-process termination at around A = 100. The observation of the afterglow of the binary neutron star merger appears to be the kilo-nova predicted in the last decade in nuclear astrophysics, and to be the great success of the field. However, the detailed study of the kilo-nova by the r-process should be a great challenge for full understanding heavy element synthesis and the neutron star merger. Nuclear physics problems are discussed for the kilonova.