Gravitational wave inference of star cluster properties from intermediate-mass black hole mergers
Abstract
Next-generation ground-based gravitational wave observatories will observe mergers of intermediate-mass black holes (IMBHs) out to high redshift. Such IMBHs can form through runaway tidal encounters in the cores of dense stellar clusters. In this paper, we ask if the gravitational wave observation of a single merger event between two IMBHs, occurring in the aftermath of the coalescence of the clusters in which they formed, can be used to infer the properties of their host clusters, such as mass, redshift, and half-mass radius. We implement an astrophysically motivated analytic model for cluster evolution and IMBH growth, and we perform IMBH binary parameter estimation using a network of three next-generation detectors. We find that inferring the structural properties of clusters in this way is challenging due to model degeneracy. However, the posteriors on the cluster formation redshifts have relatively narrow peaks, and it may still be possible to infer the cluster formation history by measuring a whole population of IMBH binary merger events.
Keywords
Cite
@article{arxiv.2501.16422,
title = {Gravitational wave inference of star cluster properties from intermediate-mass black hole mergers},
author = {Konstantinos Kritos and Luca Reali and Ken K. Y. Ng and Fabio Antonini and Emanuele Berti},
journal= {arXiv preprint arXiv:2501.16422},
year = {2025}
}
Comments
29 pages, 16 figures. Matches the published version