Year: 2026
Type: article
Abstract: The origin of black hole (BH) spins remains one of the least understood aspects of BHs. Despite many uncertainties, it is commonly assumed that if BHs originated from isolated massive star binaries, their spins should be aligned with the orbital angular momentum of the binary system. This assumption stems from the notion that BHs inherit their spins from their progenitor stars. In this study, we relax this long-held viewpoint and explore various mechanisms that can spin up BHs before or during their formation. In addition to natal spins, we discuss physical processes that can spin BHs isotropically, parallel to natal kicks, and perpendicular to natal kicks. These different mechanisms leave behind distinct imprints on the observable distributions of spin magnitudes, spin–orbit misalignments, and the effective inspiral spin of merging binaries. In particular, these mechanisms allow even the binaries originating in the field to exhibit precession and retrograde spin ( χ eff < 0). This broadens the parameter space allowed for isolated binary evolution into regimes which were previously thought to be exclusive to dynamically assembled binaries.
Source: The Astrophysical Journal
Authors: Vishal Baibhav, Vicky Kalogera
Institutions: Northwestern University, Columbia University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, Gordon and Betty Moore Foundation, Northwestern University, National Centre for Supercomputing Applications, Space Telescope Science Institute, Quest High Performance Computing, Office of Advanced Cyberinfrastructure
Awards: G1018711323, G1353381076, G1453181110, G1503004319, Track 4: Advanced CI Coordination Ecosystem: Monitoring and Measurement Services, G298330452, G3562386289, Track 1: ACCESS Resource Allocations Marketplace and Platform Services (RAMPS), G4010157413, Which Stars Lead to Black Hole Collisions?, G4263569045, G433322167, G4403015908, ACO: An Open CI Ecosystem to Advance Scientific Discovery (OpenCI), Track 3: COre National Ecosystem for CyberinfrasTructure (CONECT), G5214277425, G5367127336, G5464919783, G58316358, G6273510985, Transforming Binary-Star Simulations Across Astrophysics, G6551648957, G8108599699, G829097948, Track 2: Customized Multi-tier Assistance, Training, and Computational Help (MATCH) for End User ACCESS to CI
OpenAlex ID: W4405090759