### Black Holes and Galactic Density Cusps Spherically Symmetric Anisotropic CuspsBlack Holes and Galactic Density Cusps Spherically Symmetric Anisotropic Cusps

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 Author Delliou, Morgan Le ♦ Henriksen, Richard N. ♦ Macmillan, Joseph D. Source arXiv.org Content type Text File Format PDF Date of Submission 2009-11-11 Language English
 Subject Domain (in DDC) Computer science, information & general works ♦ Natural sciences & mathematics ♦ Astronomy & allied sciences ♦ Physics Subject Keyword Astrophysics - Astrophysics of Galaxies ♦ physics:astro-ph Abstract Aims: In this paper we study density cusps that may contain central black holes. The actual co-eval self-similar growth would not distinguish between the central object and the surroundings. Methods: To study the environment of a growing black hole we seek descriptions of steady cusps' that may contain a black hole and that retain at least a memory of self-similarity. We refer to the environment in brief as the bulge' and on smaller scales, the `halo'. Results: We find simple descriptions of the simulations of collisionless matter by comparing predicted densities, velocity dispersions and distribution functions with the simulations. In some cases central point masses may be included by iteration. We emphasize that the co-eval self-similar growth allows an explanation of the black hole bulge mass correlation between approximately similar collisionless systems. Conclusions: We have derived our results from first principles assuming adiabatic self-similarity and either self-similar virialisation or normal steady virialisation. We conclude that distribution functions that retain a memory of self-similar evolution provide an understanding of collisionless systems. The implied energy relaxation of the collisionless matter is due to the time dependence. Phase mixing relaxation may be enhanced by clump-clump interactions. Description Comment: 9 pp, 3 figs, accepted by A\&A Educational Use Research Learning Resource Type Article