2013/08/31 by Oleg Y. Gnedin, Jeremiah P. Ostriker, Scott Tremaine · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Black hole (networking) #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy formation and evolution #Galaxy groups and clusters #Globular cluster #Star cluster #Stellar mass #astro-ph.CO
paper · pdf · doi:10.1088/0004-637x/785/1/71
15 pages, submitted to ApJ, revised version after referee comments
arxiv created 2014/01/13 · openalex publication_date 2014/03/27 · arxiv updated 2015/06/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We revisit the hypothesis that dense galactic nuclei are formed from inspiraling globular clusters. Recent advances in the understanding of the continuous formation of globular clusters over cosmic time and the concurrent evolution of the galaxy stellar distribution allow us to construct a simple model that matches the observed spatial and mass distributions of clusters in the Galaxy and the giant elliptical galaxy M87. In order to compare with observations, we model the effects of dynamical friction and dynamical evolution, including stellar mass loss, tidal stripping of stars, and tidal disruption of clusters by the growing galactic nucleus. We find that inspiraling globular clusters form a dense central structure, with mass and radius comparable to the typical values in observed nuclear star clusters (NSCs) in late-type and low-mass early-type galaxies. The density contrast associated with the NSC is less pronounced in giant elliptical galaxies. Our results indicate that the NSC mass as a fraction of mass of the galaxy stellar spheroid scales as . Thus disrupted globular clusters could contribute most of the mass of NSCs in galaxies with stellar mass below 10 11 M ☉ . The inner part of the accumulated cluster may seed the growth of a central black hole via stellar dynamical core collapse, thereby relieving the problem of how to form luminous quasars at high redshift. The seed black hole may reach ∼10 5 M ☉ within ≲ 1 Gyr of the beginning of globular cluster formation.