Co-evolution of galactic nuclei and globular cluster systems

Journal Article · Thu Apr 10 04:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/785/1/71· OSTI ID:22357135

Gnedin, Oleg Y. ^[1]; Ostriker, Jeremiah P. ^[2]; Tremaine, Scott ^[3]

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1. University of Michigan, Department of Astronomy, Ann Arbor, MI 48109 (United States)
2. Princeton University Observatory, Princeton, NJ 08544 (United States)
3. Institute for Advanced Study, Princeton, NJ 08540 (United States)

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 M{sub NSC}/M{sub ∗}≈0.0025 M{sub ∗,11}{sup −0.5}. Thus disrupted globular clusters could contribute most of the mass of NSCs in galaxies with stellar mass below 10{sup 11} M {sub ☉}. 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{sup 5} M {sub ☉} within ≲ 1 Gyr of the beginning of globular cluster formation.

• OSTI ID: 22357135
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 785; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BLACK HOLES
COMPARATIVE EVALUATIONS
DENSITY
EVOLUTION
GALAXIES
GALAXY CLUSTERS
GALAXY NUCLEI
HYPOTHESIS
MASS DISTRIBUTION
MASS TRANSFER
QUASARS
RED SHIFT
SPHEROIDS
STAR CLUSTERS
STARS
STELLAR WINDS
STRIPPING