Compact Objects with Wolf-Rayet Companions: a Key Binary Configuration to Produce GravitationalWave Mergers

The properties of binaries hosting a Wolf-Rayet star and a compact object (black hole or neutron star) suggest that such systems could be the progenitors of binary compact objects merging via gravitational wave emission. We used the population-synthesis code SEVN to explore this possibility and account for current uncertainties in theoretical models. According to our simulations, most (more than about 83%) binary compact object mergers were once compact objects with Wolf-Rayet companions. Binaries like Cyg X-3, the only candidate hosting a Wolf-Rayet and a compact object observed in the Milky Way, are more likely (approximately 70%-100%) to become binary compact object mergers if they host a black hole. This work indicates that further characterization of systems like Cyg X-3 can unveil the formation mechanisms of binary compact object mergers.