Accretion disk dynamics
α-viscosity in self-similar self-gravitating models
Institut für Theoretische Physik und Astrophysik,
Chrisitan-Albrechts-Universität zu Kiel,
e-mail: email@example.com; firstname.lastname@example.org; email@example.com
2 Steward Observatory, The University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721, USA
Received: 30 July 2015
Accepted: 25 January 2016
Aims. We investigate the suitability of α-viscosity in self-similar models for self-gravitating disks with a focus on active galactic nuclei (AGN) disks.
Methods. We use a self-similar approach to simplify the partial differential equations arising from the evolution equation, which are then solved using numerical standard procedures.
Results. We find a self-similar solution for the dynamical evolution of self-gravitating α-disks and derive the significant quantities. In the Keplerian part of the disk our model is consistent with standard stationary α-disk theory, and self-consistent throughout the self-gravitating regime. Positive accretion rates throughout the disk demand a high degree of self-gravitation. Combined with the temporal decline of the accretion rate and its low amount, the model prohibits the growth of large central masses.
Conclusions. α-viscosity cannot account for the evolution of the whole mass spectrum of super-massive black holes (SMBH) in AGN. However, considering the involved scales it seems suitable for modelling protoplanetary disks.
Key words: accretion, accretion disks / turbulence / hydrodynamics / methods: analytical
© ESO, 2016