Equilibrium configurations of perfect fluid orbiting Schwarzschildde Sitter black holes
Abstract
The hydrodynamical structure of perfect fluid orbiting Schwarzschildde Sitter black holes is investigated for configurations with uniform distribution of angular momentum density. It is shown that in the blackhole backgrounds admitting the existence of stable circular geodesics, closed equipotential surfaces with a cusp, allowing the existence of toroidal accretion disks, can exist. Two surfaces with a cusp exist for the angular momentum density smaller than the one corresponding to marginally bound circular geodesics; the equipotential surface corresponding to the marginally bound circular orbit has just two cusps. The outer cusp is located nearby the static radius where the gravitational attraction is compensated by the cosmological repulsion. Therefore, due to the presence of a repulsive cosmological constant, the outflow from thick accretion disks can be driven by the same mechanism as the accretion onto the black hole. Moreover, properties of open equipotential surfaces in vicinity of the axis of rotation suggest a strong collimation effects of the repulsive cosmological constant acting on jets produced by the accretion disks.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 November 2000
 Bibcode:
 2000A&A...363..425S
 Keywords:

 ACCRETION;
 ACCRETION DISKS;
 BLACK HOLE PHYSICS;
 GRAVITATION;
 RELATIVITY;
 GALAXIES: QUASARS: GENERAL