Abstract
The radiation of linear momentum imparts a recoil (or “kick”) to the center of mass of a merging black-hole binary system. Recent numerical relativity calculations have shown that eccentricity can lead to an approximate 25% increase in recoil velocities for equal-mass, spinning binaries with spins lying in the orbital plane (“superkick” configurations) [U. Sperhake et al. Phys. Rev. D 101, 024044 (2020)]. Here we investigate the impact of nonzero eccentricity on the kick magnitude and gravitational-wave emission of nonspinning, unequal-mass black hole binaries. We confirm that nonzero eccentricities at merger can lead to kicks which are larger by up to relative to the quasicircular case. We also find that the kick velocity has an oscillatory dependence on eccentricity, which we interpret as a consequence of changes in the angle between the infall direction at merger and the apoapsis (or periapsis) direction.
- Received 28 January 2021
- Accepted 18 March 2021
DOI:https://doi.org/10.1103/PhysRevD.103.104006
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