Collisions of Molecular Clouds as a Trigger of Enhanced Accretion onto the Supermassive Black Hole in Galactic Nuclei
Abstract
On the basis of numerical calculations I will discuss to which extent direct hydrodynamical interactions of molecular clouds in the vicinity of galactic centers (within a few 100 pc) can give rise to a temporarily enhanced mass flux toward the central black hole, thus triggering or at least modulating an AGN. The models take into account (i) the mutual gravitational interaction of the clouds considered as point masses, (ii) isothermal collisions of the clouds assumed to be initially of spherical shape, (iii) tidal interactions of the clouds with the central black hole (loss of cloud material outside the cloud Hill sphere), (iv) the influence of the (linearized) tidal forces on the outcome of the hydrodynamical cloud-cloud collision process. In addition, a global bookkeeping for the most mass and the respective angular momentum gives a rough idea of the size an mass content of the accretion disk that will form out of the dispersed cloud material. If, due to the collision event, star formation is indicated (Jeans instability, appearance of collapse flow patterns), part of the cloud mass is assumed to be compactified into stars, according a given IMF.
- Publication:
-
Studies of Galaxies in the Young Universe with New Generation Telescope
- Pub Date:
- February 2004
- Bibcode:
- 2004sgyu.conf...71T