Nuclear physics of the outer layers of accreting neutron stars

Abstract

Now 50 years since the existence of the neutron star crust was proposed, we\nreview the current understanding of the nuclear physics of the outer layers of\naccreting neutron stars. Nuclei produced during nuclear burning replace the\nnascent composition of the neutron star ocean and crust. Non-equilibrium\nnuclear reactions driven by compression alter the outer thermal structure and\nchemical composition, leaving observable imprints on astronomical phenomena. As\nobservations of bursting neutron stars and cooling neutron stars have\nincreased, the recent volume of astronomical data allows new insights into the\nmicrophysics of the neutron star interior and the possibility to test nuclear\nphysics input in model calculations. Despite numerous advances in our\nunderstanding of neutron star interiors and observed neutron star phenomena,\nmany challenges remain in the astrophysics theory of accreting neutron stars,\nthe nuclear theory of neutron-rich nuclei, and the reach and precision of\nterrestrial nuclear physics experiments.\n