A Note on Bimodal Accretion Disks

Abstract

The existence of bimodal disks is investigated. Following a simple argument based on energetic considerations we show that stationary, bimodal accretion disk models in which a Shakura--Sunyaev disk (SSD) at large radii matches an advection dominated accretion flow (ADAF) at smaller radii are never possible using the standard slim disk approach, unless some extra energy flux is present. The same argument, however, predicts the possibility of a transition from an outer Shapiro--Lightman--Eardley (SLE) disk to an ADAF, and from a SLE disk to a SSD. Both types of solutions have been found.

9 pages including 9 figures, accepted for publication in The Astrophysical Journal

References in corpus (3)

• Advection-Dominated Accretion and the Spectral States of Black Hole X-Ray Binaries: Application to Nova Muscae 1991
• Advection-Dominated Flows and the X-ray Delay in the Outburst of GRO J1655-40
• On the thermal stability of transonic accretion discs

Cited by in corpus (8)

• Low-Luminosity Accretion in Black Hole X-ray Binaries and Active Galactic Nuclei
• Advective Accretion Disks and Related Problems Including Magnetic Fields
• On the limit cycle instability in magnetized accretion discs
• Shakura-Sunyaev Disk Can Smoothly Match Advection-Dominated Accretion Flow
• Advection-dominated Inflow/Outflows from Evaporating Accretion Disks
• Properties of the two-temperature corona model for active galactic nuclei and galactic black holes
• Why Canonical Disks Cannot Produce Advection Dominated Flows
• Self-similar solutions for finite size advection-dominated accretion flows