Assembling GW231123 in star clusters through the combination of stellar binary evolution and hierarchical mergers

Published in The Astrophysical Journal Letters, 994, L54, 2025

Recommended citation: Paiella, L., Ugolini, C., Spera, M., Branchesi, M., & Arca Sedda, M. (2025). "Assembling GW231123 in Star Clusters through the Combination of Stellar Binary Evolution and Hierarchical Mergers." The Astrophysical Journal Letters, 994, L54. https://ui.adsabs.harvard.edu/abs/2025ApJ...994L..54P/abstract

In this paper, we explore the dynamical formation of GW231123-like events in different cluster environments using the B-POP code, exploring how stellar mergers in primordial binaries and hierarchical mergers contribute to the assembly of these light IMBH binaries. We investigate different metallicities and spin prescriptions for the remnants of the stellar mergers and estimate the rate of these events for Milky-Way-like and dwarf galaxies.

This work was featured in a GSSI press release.

A simple scheme of one of the possible evolutionary tracks of GW231123. Feel free to use it for presentations and talks, just remember to cite us! :)

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