Modeling kicks from the merger of generic black hole binaries

Recent numerical relativistic results demonstrate that the merger of comparable-mass spinning black holes has a maximum "recoil kick" of up to similar to 4000 km s(-1). However, the scaling of these recoil velocities with mass ratio is poorly understood. We present new runs showing that the maximum possible kick perpendicular to the orbital plane does not scale as similar to eta(2) (where eta is the symmetric mass ratio), as previously proposed, but is more consistent with similar to eta(3), at least for systems with low orbital precession. We discuss the effect of this dependence on galactic ejection scenarios and retention of intermediate-mass black holes in globular clusters.