2005/06/30 by M. Mapelli, M. Colpi, A. Possenti +1 · 3 citations
Physics and Astronomy · #Angular momentum #Astrophysical Phenomena and Observations #Binary black hole #Binary number #Binary star #Black hole (networking) #Globular cluster #Pulsars and Gravitational Waves Research #Specific relative angular momentum #Stars #Stellar, planetary, and galactic studies #Velocity dispersion #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.09653.x
published as Mon.Not.Roy.Astron.Soc. 364 (2005) 1315-1326 · 15 pages, 9 figures, replaced with revised version, accepted for publication in MNRAS
arxiv created 2005/09/28 · openalex publication_date 2005/11/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We explore the signatures that a binary intermediate-mass black hole (IMBH) imprints on the velocity and on the angular momentum of globular cluster (GC) stars. Simulating three-body encounters between a star and a binary IMBH, we find that the binary IMBH generates a family of a few hundred stars (∼100–300) which remain bound to the GC and have velocity significantly higher than the dispersion velocity. For this reason, we term them ‘suprathermal’ stars. We also notice that, after the interaction, a considerable fraction (55–70 per cent) of stars tend to align their orbital angular momentum with the angular momentum of the binary IMBH, introducing an anisotropy in the angular momentum distribution of cluster stars. We simulate the dynamical evolution of these suprathermal stars before thermalization and find that these stars tend to cluster at a distance of few core radii from the GC centre. We conclude that the detectability of such signatures appears problematic with present telescopes.