Simulations of the Progenitors of Black Hole–Neutron Star Gravitational Wave Sources

Recent discoveries of gravitational wave (GW) events most likely originating from black hole (BH) + neutron star (NS) mergers reveal the existence of BH+NS binaries. The formation of BH+NS binaries and their merger rates through isolated binary evolution have been investigated extensively with population synthesis simulations. A detailed stellar evolution modeling of the formation of this population, however, is missing from the literature. In this work, we create the first complete 1D model of more than 30 BH+NS progenitor systems, which are calculated self-consistently until collapse of the iron core with infall velocity exceeding 1000 km s −1 . Focusing on the progenitors of BH–NS GW sources, we apply the MESA code starting from a post-common-envelope binary with short orbital period (