Magnetization, accretion, and outflows in young stellar objects


Por: Shu F.H., Galli D., Lizano S., Cai M.J.

Publicada: 1 ene 2007
Categoría: Astronomy and Astrophysics

Resumen:
Abstract We review the theory of the formation and gravitational collapse of magnetized molecular cloud cores, leading to the birth of T Tauri stars surrounded by quasi-Keplerian disks whose accretion is driven by the magnetorotational instability (MRI). Some loss of magnetic flux during the collapse results typically in a dimensionless mass-to-flux ratio for the star plus disk of 0 4. Most of the mass ends up in the star, while almost all of the flux and the angular momentum ends up in the disk; therefore, a known mass for the central star implies a computable flux in the surrounding disk. A self-contained theory of the MRI that drives the viscous/resistive spreading in such circumstances then yields the disk radius needed to contain the flux trapped in the disk as a function of the age t. This theory yields analytic predictions of the distributions with distance from the central star of the surface density (), the vertical magnetic field Bz(), and the (sub-Keplerian) angular rotation rate (). We discuss the implications of this picture for disk-winds, X-winds, and funnel flows, and we summarize the global situation by giving the energy and angular-momentum budget for the overall problem. © 2007 International Astronomical Union.

Filiaciones:
Shu F.H.:
 Department of Physics, University of California, San Diego, CA 92093, United States

Galli D.:
 INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, Firenze I-50125, Italy

Lizano S.:
 CRyA, Universidad Nacional Autónoma de México, Apdo. Postal 72-3, 58089 Morelia, Mexico

Cai M.J.:
 Academia Sinica, Institute of Astronomy and Astrophysics, Taiwan
ISSN: 17439213
Editorial
CAMBRIDGE UNIV PRESS, THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE CB2 1RP, CAMBS, ENGLAND, Reino Unido
Tipo de documento: Conference Paper
Volumen: 3 Número: 1 S2
Páginas: 249-264
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