Tilted Thick-disk Accretion onto a Kerr Black Hole

We present the first results from fully general relativistic numerical studies of thick-disk accretion onto a rapidly-rotating (Kerr) black hole with a spin axis that is tilted (not aligned) with the angular momentum vector of the disk. We initialize the problem with the solution for an aligned, constant angular momentum, accreting thick disk around a black hole with spin a/M = J/M = +0.9 (prograde disk). The black hole is then instantaneously tilted, through a change in the metric, by an angle β0. In this work we report results with β0 = 0, 15, and 30 ◦. The disk is allowed to respond to the LenseThirring precession of the tilted black hole. We find that the disk settles into a quasi-static, twisted, warped configuration with the Lense-Thirring precession dominating out to a radius analogous to the Bardeen-Petterson transition in tilted Keplerian disks. Subject headings: accretion, accretion disks — black hole physics — hydrodynamics — methods: numerical — relativity