Close encounters of stars with stellar-mass black hole binaries
ABSTRACT

Many astrophysical environments, from star clusters and globular clusters to the discs of active galactic nuclei, are characterized by frequent interactions between stars and the compact objects that they leave behind. Here, using a suite of 3D hydrodynamics simulations, we explore the outcome of close interactions between $1\, \mathrm{M}_{\odot }$ stars and binary black holes (BBHs) in the gravitational wave regime, resulting in a tidal disruption event (TDE) or a pure scattering, focusing on the accretion rates, the back reaction on the BH binary orbital parameters, and the increase in the binary BH effective spin. We find that TDEs can make a significant impact on the binary orbit, which is often different from that of a pure scattering. Binaries experiencing a prograde (retrograde) TDE tend to be widened (hardened) by up to $\simeq 20{{\ \rm per\ cent}}$. Initially circular binaries become more eccentric by $\lesssim 10{{\ \rm per\ cent}}$ by a prograde or retrograde TDE, whereas the eccentricity of initially eccentric binaries increases (decreases) by a retrograde (prograde) TDE by $\lesssim 5{{\ \rm per\ cent}}$. Overall, a single TDE can generally result in changes of the gravitational-wave-driven merger time-scale by order unity. The accretion rates of both black holes more »

Authors:
; ;
Publication Date:
NSF-PAR ID:
10371036
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
516
Issue:
2
Page Range or eLocation-ID:
p. 2204-2217
ISSN:
0035-8711
Publisher:
Oxford University Press
National Science Foundation
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2. ABSTRACT

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4. ABSTRACT

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