Global Self-Similar Protostellar Disk/Wind Models

Abstract

The magnetocentrifugal disk wind mechanism is the leading candidate for producing the large-scale, bipolar jets commonly seen in protostellar systems. I present a detailed formulation of a global, radially self-similar model for a non-ideal disk that launches a magnetocentrifugal wind. This formulation generalizes the conductivity tensor formalism previously used in radially localized disk models. The model involves matching a solution of the equations of non-ideal MHD describing matter in the disk to a solution of the equations of ideal MHD describing a "cold" wind. The disk solution must pass smoothly through the sonic point, the wind solution must pass smoothly through the Alfvén point, and the two solutions must match at the disk/wind interface. This model includes for the first time a self-consistent treatment of the evolution of magnetic flux threading the disk, which can change on the disk accretion timescale. The formulation presented here also allows a realistic conductivity profile for the disk to be used in a global disk/wind model for the first time. The physical constraints on the model solutions fix the distribution of the magnetic field threading the disk, the midplane accretion speed, and the midplane migration speed of flux surfaces. I present a representative solution that corresponds to a disk in the ambipolar conductivity regime with a nominal neutral-matter--magnetic-field coupling parameter that is constant along field lines, matched to a wind solution. I conclude with a brief discussion of the importance of self-similar disk/wind models in studying global processes such as dust evolution in protostellar systems.

18 pages, 8 figures, 1 table, accepted to ApJ

References in corpus (6)

• Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
• Magnetic fields in protoplanetary disks
• MHD simulations of jet acceleration from Keplerian accretion disks: the effects of disk resistivity
• Advection of Magnetic Fields in Accretion Disks: Not So Difficult After All
• Advection/Diffusion of Large-Scale B-Field in Accretion Disks
• Angular momentum transport in protostellar discs

Cited by in corpus (8)

• Wind-driven Accretion in Protoplanetary Disks. I: Suppression of the Magnetorotational Instability and Launching of the Magnetocentrifugal Wind
• Magneto-thermal Disk Wind from Protoplanetary Disks
• Magnetorotational Instability Driven Accretion in Protoplanetary Disks
• Dust Transport and Processing in Centrifugally Driven Protoplanetary Disk Winds
• Centrifugally driven winds from protostellar accretion discs. I - Formulation and initial results
• Inner dusty regions of protoplanetary discs -- II. Dust dynamics driven by radiation pressure and disc winds
• Type I Planet Migration in a Magnetized Disk. I. Effect of Large-Scale Vertical and Azimuthal Field Components
• Depletion of Moderately Volatile Elements by Open-System loss in the Early Solar Nebula