Publication date: n/a 2005
Abstract:
Surprisingly, the relict cosmological constant has a crucial influence
on properties of accretion discs orbiting black holes in quasars and
active galactic nuclei. We show it by considering basic properties of
both the geometrically thin and thick accretion discs in the Kerr-de
Sitter black hole (naked-singularity) spacetimes. Both thin and thick
discs must have an outer edge allowing outflow of matter into the outer
space, located nearby the so-called static radius, where the
gravitational attraction of a black hole is balanced by the cosmological
repulsion. Jets produced by thick discs can be significantly collimated
after crossing the static radius. Extension of discs in quasars is
comparable with extension of the associated galaxies, indicating a
possibility that the relict cosmological constant puts an upper limit on
extension of galaxies.
Authors:
Stuchlík, Zdeněk;