2003/01/31 by J. Gracia, J. Peitz, Ch. Keller +1 · 1 citation
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2003.06832.x
published as Mon.Not.Roy.Astron.Soc. 344 (2003) 468 · 6 pages, 3 figures. Revised version, added system of equations. Accepted for publication in MNRAS
arxiv created 2003/05/26 · openalex publication_date 2003/09/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We consider time-dependent models for rotating accretion flows on to black holes, where a transition takes place from an outer cooling-dominated disc to a radiatively inefficient flow in the inner region. In order to allow for a transition of this type we solve the energy equation, both for the gas and for the radiation field, including a radiative cooling flux and a turbulent convective heat flux directed along the negative entropy gradient. The transition region is found to be highly variable, and a corresponding variation is expected for the associated total luminosity. In particular, rapid oscillations of the transition radius are present on a time-scale comparable with the local Keplerian rotation time. These oscillations are accompanied by a quasi-periodic modulation of the mass flux at the outer edge of the advection-dominated accretion flow (ADAF). We speculate about the relevance for the high-frequency quasi-periodic oscillation phenomenon.