Consequences of Triaxiality for Gravitational Wave Recoil of Black Holes

Coalescing binary black holes experience a ``kick'' due to anisotropicemission of gravitational waves with an amplitude as great as 200$ km/s. Weexamine the orbital evolution of black holes that have been kicked from thecenters of triaxial galaxies. Time scales for orbital decay are generallylonger in triaxial galaxies than in equivalent spherical galaxies, since akicked black hole does not return directly through the dense center where thedynamical friction force is highest. We evaluate this effect by constructingself-consistent triaxial models and integrating the trajectories of massiveparticles after they are ejected from the center; the dynamical friction forceis computed directly from the velocity dispersion tensor of the self-consistentmodel. We find return times that are several times longer than in a sphericalgalaxy with the same radial density profile, particularly in galaxy models withdense centers, implying a substantially greaComment: 28 pages, including 13 eps figures. Submitted to Ap