Abstract
The relative spin orientations of black holes (BHs) in binaries encode their evolutionary history: BHs assembled dynamically should have isotropically distributed spins, while spins of BHs originating in the field should be aligned with the orbital angular momentum. In this article, we introduce a simple population model for these dynamical and field binaries that uses spin orientations as an anchor to disentangle these two evolutionary channels. We then analyze binary BH mergers in the Third Gravitational-Wave Transient Catalog (GWTC-3) and ask whether BHs from the isotropic-spin population possess different distributions of mass ratios, spin magnitudes, or redshifts from the preferentially aligned-spin population. We find no compelling evidence that binary BHs in GWTC-3 have different source-property distributions depending on their spin alignment, but we do find that the dynamical and field channels cannot both have mass-ratio distributions that strongly favor equal masses. We give an example of how this can be used to provide insights into the various processes that drive these BHs to merge. We also find that the current detections are insufficient in extracting differences in spin magnitude or redshift distributions of isotropic and aligned-spin populations.
| Original language | English (US) |
|---|---|
| Article number | 50 |
| Journal | Astrophysical Journal |
| Volume | 946 |
| Issue number | 1 |
| DOIs | |
| State | Published - Mar 1 2023 |
Funding
We are grateful to Salvatore Vitale and Sylvia Biscoveanu for the helpful discussions. This material is based upon work supported by NSF\u2019s LIGO Laboratory, which is a major facility fully funded by the National Science Foundation. Z.D. acknowledges support from the CIERA Board of Visitors Research Professorship and NSF grant PHY-2207945. V.K. was partially supported through a CIFAR Senior Fellowship, a Guggenheim Fellowship, the Gordon and Betty Moore Foundation (grant award GBMF8477), and from Northwestern University, including the Daniel I. Linzer Distinguished University Professorship fund. This research was supported in part through the computational resources and staff contributions provided for 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.
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science