New gravitational-wave data support a bimodal black-hole mass distribution
Abstract
Detailed stellar evolution and supernova models yield a bimodal black-hole mass distribution with a narrow peak around 10 solar masses from stars within a narrow range of progenitor properties and a second broader peak starting around 20 solar masses from very massive progenitors. This bimodal black-hole mass distribution leads to a characteristic distribution of chirp masses of merging binary black holes, with two main peaks arising from the merger of two black holes where both come either from the low- or the high-mass peak and a smaller peak in between from the mixed merger of a low-mass and a high-mass black hole. We carry out a population synthesis study of binary black hole formation and compare the results to the observed chirp masses of gravitational-wave events. We find that only the bimodal black-hole mass prescription is able to reproduce the structure of peaks and gaps in the observed chirp-mass distribution, which is not matched by predictions from other remnant mass prescriptions in the literature.
Keywords
Cite
@article{arxiv.2508.20787,
title = {New gravitational-wave data support a bimodal black-hole mass distribution},
author = {R. Willcox and F. R. N. Schneider and E. Laplace and Ph. Podsiadlowski and K. Maltsev and I. Mandel and P. Marchant and H. Sana and T. Li and T. Hertog},
journal= {arXiv preprint arXiv:2508.20787},
year = {2025}
}