Binary Disruption by Massive Black Holes: Hypervelocity Stars, S Stars, and Tidal Disruption Events
Abstract
We examine whether disrupted binary stars can fuel black hole growth. In this mechanism, tidal disruption produces a single hypervelocity star (HVS) ejected at high velocity and a former companion star bound to the black hole. After a cluster of bound stars forms, orbital diffusion allows the black hole to accrete stars by tidal disruption at a rate comparable to the capture rate. In the Milky Way, HVSs and the S star cluster imply similar rates of 10-5 to 10-3 yr-1 for binary disruption. These rates are consistent with estimates for the tidal disruption rate in nearby galaxies and imply significant black hole growth from disrupted binaries on 10 Gyr timescales.
- Publication:
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The Astrophysical Journal
- Pub Date:
- April 2012
- DOI:
- 10.1088/2041-8205/749/2/L42
- arXiv:
- arXiv:1203.6685
- Bibcode:
- 2012ApJ...749L..42B
- Keywords:
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- Galaxy: halo;
- Galaxy: kinematics and dynamics;
- Galaxy: stellar content;
- Galaxy: structure;
- stars: early-type;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- ApJ Letters, accepted