Abstract
There are few observed high-mass X-ray 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 gravitational-wave (GW) observations. We investigate the role that X-ray 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 >35M ⊙ in our simulated populations. Furthermore, we find the probability that a detectable HMXB will merge as a BBH system within a Hubble time is ≃0.6%. Thus, it is unsurprising that no currently observed HMXB is predicted to form a merging BBH with high probability.
| Original language | English (US) |
|---|---|
| Article number | 4 |
| Journal | Astrophysical Journal |
| Volume | 946 |
| Issue number | 1 |
| DOIs | |
| State | Published - Mar 1 2023 |
Funding
The authors thank Scott Coughlin and Katie Breivik for their assistance with COSMIC. We thank Jeff Andrews, Pablo Marchant, Ilya Mandel, and Neta Bahcall for insightful conversations and input on our results. C.L. acknowledges support from CIERA and Northwestern University. Support for M.Z. was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51474.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. C.P.L.B. acknowledges support from the CIERA Board of Visitors Research Professorship and from STFC grant ST/V005634/1. Z.D. also acknowledges support from the CIERA Board of Visitors Research Professorship. V.K. was partially supported through a CIFAR Senior Fellowship, a Guggenheim Fellowship, and the Gordon and Betty Moore Foundation (grant award GBMF8477). This work utilized the computing resources at CIERA provided by the Quest high-performance computing facility at Northwestern University, which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology, and used computing resources at CIERA funded by NSF PHY-1726951. The data that support the findings of this study are openly available from Zenodo https://doi.org/10.5281/zenodo.7216270.
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science