On the dynamo driven accretion disks
| dc.creator | Ma, Chun-yu | |
| dc.creator | Biermann, Peter L | |
| dc.date | 1997-11-26 | |
| dc.date.accessioned | 2026-07-07T02:25:15Z | |
| dc.date.available | 2026-07-07T02:25:15Z | |
| dc.description | We add the $α-$ effect in the dynamo driven accretion disk model proposed by Tout & Pringle (1992), i.e., a dynamo model depends on the physical processes such as Parker instability, Balbus-Hawley instability, magnetic field reconnection and $α-ω$ mean field dynamo as well. The $α-$ effect in the dynamo mechanism is determined by the strength of turbulence of the accretion flow. When the turbulent Mach number $M_t$ is less than 0.25, the solutions of the magnetic fields oscillate around their equilibrium values. The increase of the value of $M_t$ makes the amplitude of the oscillation smaller and the period longer, but does not affect the equilibrium values. The Shakura-Sunyaev viscosity parameter $α_{SS}$ oscillates around the equilibrium value of 0.33. When the turbulent Mach number $M_t$ is larger than 0.25, the magnetic field components reach a stable state. In the non-linear dynamo region, the critical turbulent Mach number $M_t$ is 0.44 rather than 0.25. The oscillating magnetic fields and viscosity parameter can explain the basic properties of the dwarf nova eruptions and some properties of quiescent disks (Armitage et al. 1996). | |
| dc.description | 19 pages, 5 eps figures, uses aasms4.sty, accepted to A&A | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9711308 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9711308 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/11855 | |
| dc.subject | Astrophysics | |
| dc.title | On the dynamo driven accretion disks | |
| dc.type | text |