The Missing Link Between Black Holes in High-Mass X-ray Binaries and Gravitational-Wave Sources: Observational Selection Effects [HEAP]

http://arxiv.org/abs/2210.01825


There are few observed high-mass X-ray binaries (HMXBs) that harbor massive black holes, and none are likely to result in a binary black hole (BBH) that merges within a Hubble time; however, we know that massive merging BBHs exist from gravitational-wave observations. We investigate the role that X-ray and gravitational-wave observational selection effects play in determining the properties of their respective detected binary populations. We confirm that, as a result of selection effects, observable HMXBs and observable BBHs form at different redshifts and metallicities, with observable HMXBs forming at much lower redshifts and higher metallicities than observable BBHs. We also find disparities in the mass distributions of these populations, with observable merging BBH progenitors pulling to higher component masses relative to the full observable HMXB population. Fewer than $3\%$ of observable HMXBs host black holes $> 35M_{\odot}$ in our simulated populations. Furthermore, we find the probability that a detectable HMXB will merge as a BBH system within a Hubble time is $\simeq 0.6\%$. Thus, it is unsurprising that no currently observed HMXB is predicted to form a merging BBH with high probability.

Read this paper on arXiv…

C. Liotine, M. Zevin, C. Berry, et. al.
Thu, 6 Oct 22
22/77

Comments: 16 pages, 6 figures, 1 table