Ulrich Sperhake (presentation given by Vitor Cardoso)

California Institute of Technology

High energy grazing collisions of black holes

We investigate high-energy collisions of equal-mass black-hole binaries with non-zero impact parameters. The first half of the talk discusses non-spinning binaries and identifies zoom-whirl behaviour as well as gravitational radiation emitted by the binaries as a function of the impact parameter. We observe enormous luminosities not that far below the Dyson limit and obtain final spins close to the Kerr limit for impact parameters near the threshold of immediate merger. Second, we discuss the recoil obtained from such collisions for so-called superkick configurations. Specifically, we wish to address the question whether the large kicks are predominantly the result of the black-hole merger phase.