Speaker
Description
One of the main uncertainties in understanding the pathway of stars becoming gravitational-wave sources according to the isolated binary channel are binary interaction physics. Important constraints, such as on the mass-transfer efficiency or the spin-up of the mass-gaining star, that determine the future evolution of the system, are lacking. Those can be provided by detecting and characterizing the intermediate phases in such binary-evolution pathways, where one component is a compact object already, and the other one is still a fairly unevolved OB-type star.
While over 1000 such binary systems are predicted to exist in the Milky Way alone, only recently the first two quiescent OB+black hole (BH) systems were detected. On the other hand, many BH impostors were reported that were later shown to be false-positives. In my talk, I will demonstrate the difficulties of finding such systems by explaining the many pitfalls we uncovered when exposing one of the impostors. I will further describe how more such binaries can be detected by explaining how we found the only two yet unchallenged OB+BH systems. I will discuss what can be learned from those about the future evolution of such systems, which is crucial for our understanding of the formation of double-compact objects and gravitational waves.
