Disk Winds Driven by Magnetorotational Instability and Dispersal of Proto-Planetary Disks
| Autor: | T. K. Suzuki, Shu-ichiro Inutsuka |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Physics
Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) FOS: Physical sciences Astronomy and Astrophysics Astrophysics Breakup Magnetic field Momentum Space and Planetary Science Magnetorotational instability Poynting vector Physics::Space Physics Differential rotation Astrophysics::Solar and Stellar Astrophysics Magnetic pressure Astrophysics::Earth and Planetary Astrophysics Magnetohydrodynamics Astrophysics::Galaxy Astrophysics |
| Popis: | By performing local three-dimensional MHD simulations of stratified accretion disks, we investigate disk winds driven by MHD turbulence. Initially given weak vertical magnetic fields are effectively amplified by magnetorotational instability and winding due to differential rotation. Large scale channel flows develop most effectively at 1.5 - 2 times the scale heights where the magnetic pressure is comparable to but slightly smaller than the gas pressure. The breakup of these channel flows drives structured disk winds by transporting the Poynting flux to the gas. These features are universally observed in the simulations of various initial fields. This disk wind process should play an essential role in the dynamical evaporation of proto-planetary disks. The breakup of channel flows also excites the momentum fluxes associated with Alfvenic and (magneto-)sonic waves toward the mid-plane, which possibly contribute to the sedimentation of small dust grains in protoplanetary disks. 6 pages, 5 figures embedded, ApJL in press |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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