2025/10/08 by D. Marín Pina, Pina, Daniel Marín, Mark Gieles +5 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Gravitation Theories #Earth Systems and Cosmic Evolution #FOS: Physical sciences
paper · pdf · doi:10.48550/arxiv.2510.07021
openalex publication_date 2025/10/08 · openalex created_date 2025/10/18 · openalex updated_date 2026/07/28
The Gaia collaboration announced the discovery of a massive black hole (BH) with a low-mass giant star companion, Gaia BH3, located in the ED-2 stellar stream. The properties of Gaia BH3 bridge the gap between known Milky Way BHs and extragalactic BHs found with gravitational waves (GWs). We aim to determine the most likely formation scenario for Gaia BH3 in the progenitor cluster of the ED-2 stream. We perform N-body simulations of that progenitor cluster and find that, most likely, Gaia BH3 formed from a stellar binary that formed during cluster formation, which then underwent multiple dynamical interactions that significantly altered its properties, including exchanging the companion star. We highlight the importance of cluster dynamics and discard a formation scenario where it evolved in quasi-isolation.