Finite collisionless accretion disks in the Kerr spacetime

Abstract

We construct general-relativistic kinetic models of stationary finite accretion disks in the Kerr spacetime. Our analysis generalizes a previous model of razor-thin accretion disks of collisionless gas in the Kerr spacetime, extending to infinity in the equatorial plane. We investigate monoenergetic configurations, as well as models characterized by Maxwell-J\"{u}ttner type distributions at the outer edge of the disk. In both cases, we consider particles moving along orbits reaching the outer boundary of the disk, either plunging into the black hole, or scattered by the centrifugal barrier. For Maxwell-J\"{u}ttner models, the location of the outer disk boundary affects the mass and angular momentum accretion rates at a similar order of magnitude as the temperature parameter in the assumed Maxwell-J\"{u}ttner distribution.