Open AccessA massive thick disc around a massive black hole and its runaway instability
Author(s) -
Lu Y.,
Cheng K. S.,
Yang L. T.,
Zhang L.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03253.x
Subject(s) - physics , angular momentum , instability , black hole (networking) , accretion (finance) , torus , astrophysics , specific relative angular momentum , momentum (technical analysis) , mechanics , classical mechanics , total angular momentum quantum number , angular momentum coupling , geometry , computer network , routing protocol , routing (electronic design automation) , computer science , link state routing protocol , mathematics , finance , economics
We investigate the runaway instability of configurations consisting of a massive dense but non‐self‐gravitating thick disc/torus surrounding a massive black hole (MBH). We limit our model parameters to values that result in a self‐consistent thick disc around an MBH. We identify, analytically, the index of the angular momentum distribution that will form a thick disc as an initial equilibrium state, and obtain the mass ratio of the disc to the central black hole for which the disc is dominated by the radiation pressure. In our theoretical framework we find that a self‐consistent thick disc with constant angular momentum leads to a runaway instability on a dynamical time‐scale. However, even a slight increase of the specific angular momentum outwards has a strong stabilizing effect on the accretion process. Finally, we discuss our results and present possible applications to high‐energy emission.