There are few observed highmass Xray binaries (HMXBs) that harbor massive black holes (BHs), 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 gravitationalwave (GW) observations. We investigate the role that Xray and GW observational selection effects play in determining the properties of their respective detected binary populations. We find that, as a result of selection effects, detectable HMXBs and detectable BBHs form at different redshifts and metallicities, with detectable HMXBs forming at much lower redshifts and higher metallicities than detectable BBHs. We also find disparities in the mass distributions of these populations, with detectable merging BBH progenitors pulling to higher component masses relative to the full detectable HMXB population. Fewer than 3% of detectable HMXBs host BHs >35
This content will become publicly available on April 1, 2023
 Award ID(s):
 1912648
 Publication Date:
 NSFPAR ID:
 10391494
 Journal Name:
 The Astrophysical Journal Letters
 Volume:
 929
 Issue:
 2
 Page Range or eLocationID:
 L26
 ISSN:
 20418205
 Sponsoring Org:
 National Science Foundation
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