Modeling gravitational recoil from precessing highly spinning unequal-mass black-hole binaries

We measure the gravitational recoil for unequal-mass black-hole binary mergers, with the larger black hole having intrinsic spin a/m^H=0.8, and the smaller black hole nonspinning. We choose our configurations such that, initially, the spins lie on the orbital plane. The spin and orbital plane precess significantly (we introduce a technique to identify the orbital plane at merger), and we find that the out-of plane recoil (i.e. the recoil perpendicular to the orbital plane around merger) varies as η²/(1+q), in agreement with our previous prediction, based on the post-Newtonian scaling.