The Shakura-Sunyaev Disk Can Smoothly Match an Advection-dominated Accretion Flow
Abstract
We use the standard Runge-Kutta method to solve a set of basic equations describing black hole accretion flows composed of two-temperature plasma. We do not invoke any extra energy transport mechanism, such as thermal conduction, and we do not specify any ad hoc outer boundary condition for the advection-dominated accretion flow (ADAF) solution. We find that in the case of high viscosity and nonzero radiative cooling, the ADAF solution can have an asymptotic approach to the Shakura-Sunyaev disk (SSD) solution and that the SSD-ADAF transition radius is close to the central black hole. Our results further prove the mechanism of thermal instability-triggered SSD-ADAF transition suggested previously by Takeuchi & Mineshige and Gu & Lu.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2004
- DOI:
- 10.1086/382209
- arXiv:
- arXiv:astro-ph/0401018
- Bibcode:
- 2004ApJ...602L..37L
- Keywords:
-
- Accretion;
- Accretion Disks;
- Black Hole Physics;
- Hydrodynamics;
- Astrophysics
- E-Print:
- 10 pages, 2 figures, accepted for publication in ApJ Letters