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arXiv · 1807.10765

Hypervelocity binaries from close encounters with a SMBH-IMBH binary: orbital properties and diagnostics

Yi-Han Wang·Nathan Leigh·Alberto Sesana·Rosalba Perna
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Abstract

Hypervelocity binaries (HVBs) can be produced by a close encounter between stellar binaries and supermassive black hole (SMBH)-intermediate massive black hole (IMBH) binaries. We perform scattering experiments between tight stellar binaries and an SMBH-IMBH binary (within the observationally allowed parameters), using high-precision N-body integrations. Simulation results show that only a few HVBs can be produced in the Galactic center if it harbors a $4\times10^3M_\odot$ IMBH. However, we find that tight HVBs can be efficiently produced in prograde coplanar orbits with respect to the SMBH-IMBH binary. Therefore, the trajectories of the HVBs provide a promising way to constrain the IMBH orbital plane, if one exists. More importantly, we find that the ejected tight binaries are eccentric. For other galaxies hosting equal-mass SMBH binaries for which the HVB ejection rate is much higher relative to SMBH-IMBH binaries, these ejected compact binaries constitute promising extragalactic merger sources that could be detected by gravitational wave detectors.

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Yi-Han Wang, Nathan Leigh, Alberto Sesana, Rosalba Perna. 2018-07-27. Hypervelocity binaries from close encounters with a SMBH-IMBH binary: orbital properties and diagnostics. https://doi.org/10.1093/mnras%2Fsty2866

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