On the Astrophysical Origin of Binary Black Hole Subpopulations: A Tale of Three Channels?
Published in ArXiv for now, 2026
This project investigates the astrophysical origins of merging binary black holes using gravitational wave data from the LIGO–Virgo–KAGRA collaboration. Recent observations suggest that the population of detected mergers is not uniform, but instead reflects contributions from multiple formation pathways.
In this work, we apply parametrized Bayesian mixture modeling to the observed population, using distributions of black hole masses, spins, and redshift. We find that the data are well described by three distinct subpopulations, each with different statistical properties. These subpopulations are consistent with expectations from different formation channels, such as isolated binary evolution, dynamical formation in dense stellar environments, and hierarchical mergers involving previously merged black holes.
Our results show that key features in the observed population—such as structure in the mass distribution and changes in spin properties—can emerge naturally from the combination of these subpopulations, without explicitly imposing such transitions in the model.
Overall, this work provides a data-driven framework for interpreting the growing population of gravitational wave detections and for connecting observational trends to underlying astrophysical formation scenarios.
Recommended citation: arXiv:2603.17987 [astro-ph.HE]
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