Evolution of bimodal accretion flows

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...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Monthly notices of the Royal Astronomical Society Jg. 344; H. 2; S. 468 - 472
Hauptverfasser: Gracia, J., Peitz, J., Keller, Ch, Camenzind, M.
Format: Journal Article
Sprache:Englisch
Veröffentlicht: Oxford, UK Blackwell Science Ltd 11.09.2003
Schlagworte:
accretion
accretion discs
accretion, accretion discs
black hole physics
convection
hydrodynamics
instabilities
ISSN:0035-8711, 1365-2966
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung: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.
Bibliographie:istex:CF091B9DD000477CEF3EB0BD05DD7284CA158678
ark:/67375/HXZ-5GKZP4WV-B
ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ISSN:0035-8711
1365-2966
DOI:10.1046/j.1365-8711.2003.06832.x