Mapping progenitors of binary black holes and neutron stars with binary population synthesis

Abstract

ABSTRACT The first directly observed gravitational wave event, GW150914, featuring the merger of two massive black holes, highlighted the need to determine how these systems of compact remnant binaries are formed. We use the binary population synthesis code Compact Object Synthesis and Monte Carlo Investigation Code (COSMIC) to predict the types of massive stars that will show significant radial velocity (RV) variations, indicative of a potential compact object (i.e. a black hole or neutron star) orbiting the star. We ‘observe’ the binaries generated in the populations with a similar number of epochs and RV accuracy as planned for the Milky Way Mapper (MWM) survey. In this analysis, we are especially interested in systems where a compact remnant is orbiting a massive O or B star as these systems survived the first supernova and neutron star kick. We test the ability of the Milky Way Mapper observing strategy to distinguish among different mass-loss and kick prescriptions. We find that Wolf–Rayet stars or hot subdwarfs in binaries could be detectable (i.e. luminous, high ΔRVmax), viable progenitors of such objects, while the different prescriptions primarily affect the number of sources.