Angular momentum transport in protostellar discs

Abstract

Angular momentum transport in protostellar discs can take place either radially, through turbulence induced by the magnetorotational instability (MRI), or vertically, through the torque exerted by a large-scale magnetic field that threads the disc. Using semi-analytic and numerical results, we construct a model of steady-state discs that includes vertical transport by a centrifugally driven wind as well as MRI-induced turbulence. We present approximate criteria for the occurrence of either one of these mechanisms in an ambipolar diffusion-dominated disc. We derive ``strong field'' solutions in which the angular momentum transport is purely vertical and ``weak field'' solutions that are the stratified-disc analogues of the previously studied MRI channel modes; the latter are transformed into accretion solutions with predominantly radial angular-momentum transport when we implement a turbulent-stress prescription based on published results of numerical simulations. We also analyze ``intermediate field strength'' solutions in which both modes of transport operate at the same radial location; we conclude, however, that significant spatial overlap of these two mechanisms is unlikely to occur in practice. To further advance this study, we have developed a general scheme that incorporates also the Hall and Ohm conductivity regimes in discs with a realistic ionization structure.

8 pages, 4 figures, 1 table; accepted for publication in MNRAS

References in corpus (18)

• The Formation and Structure of a Strongly Magnetized Corona above Weakly Magnetized Accretion Disks
• Linear Analysis of the Hall Effect in Protostellar Disks
• Angular Momentum Transport by MHD Turbulence in Accretion Disks: Gas Pressure Dependence of the Saturation Level of the Magnetorotational Instability
• The Balbus-Hawley instability in weakly ionised discs
• The Effect of the Hall Term on the Nonlinear Evolution of the Magnetorotational Instability: II. Saturation Level and Critical Magnetic Reynolds Number
• Magnetized Accretion-Ejection Structures: 2.5D MHD simulations of continuous Ideal Jet launching from resistive accretion disks
• The Effect of the Hall Term on the Nonlinear Evolution of the Magnetorotational Instability: I. Local Axisymmetric Simulations
• Reduction of chemical networks. II. Analysis of the fractional ionisation in protoplanetary discs
• Saturation and Thermalization of the Magnetorotational Instability: Recurrent Channel Flows and Reconnections
• Launching of jets and the vertical structure of accretion disks
• Star Formation and the Hall Effect
• Predicted rotation signatures in MHD disc winds and comparison to DG Tau observations
• Self-similar Collapse of Rotating Magnetic Molecular Cloud Cores
• Magnetorotational instability in protoplanetary discs
• Magnetorotational instability in stratified, weakly ionised accretion discs
• The Acceleration Mechanism of Resistive MHD Jets Launched from Accretion Disks
• Launching jets from the boundary layer of accretion disks in young stellar objects
• Are Magnetic Wind-Driving Disks Inherently Unstable?

Cited by in corpus (36)

• Wind-driven Accretion in Protoplanetary Disks. I: Suppression of the Magnetorotational Instability and Launching of the Magnetocentrifugal Wind
• Turbulence In the Outer Regions of Protoplanetary Disks. II. Strong Accretion Driven by a Vertical Magnetic Field
• Magnetorotational Instability Driven Accretion in Protoplanetary Disks
• Magnetically driven accretion in protoplanetary discs
• Hall diffusion and the magnetorotational instability in protoplanetary discs
• A Disk-Wind Model for the Near-Infrared Excess Emission in Protostars
• Advection/Diffusion of Large-Scale B-Field in Accretion Disks
• Signatures of MRI-Driven Turbulence in Protoplanetary Disks: Predictions for ALMA Observations
• The Role of Tiny Grains on the Accretion Process in Protoplanetary Disks
• Wind-driving protostellar accretion discs. I. Formulation and parameter constraints
• Magnetically-driven jets and winds from weakly magnetized accretion disks
• Origin of Weak Turbulence in the Outer Regions of Protoplanetary Disks
• Wind-driven Accretion in Transitional Protostellar Disks
• Jet enhanced accretion growth of supermassive black holes
• Modeling the delivery of dust from discs to ionized winds
• MRI channel flows in vertically-stratified models of accretion disks
• The Challenge of Sub-Keplerian Rotation for Disk Winds
• Wind-driving protostellar accretion discs. II. Numerical method and illustrative solutions
• Magnetorotational instability in protoplanetary discs: The effect of dust grains
• Towards a New Standard Model for Black Hole Accretion
• On the interpretation of the apparent existence of a preferred magnetic polarity in extragalactic jet sources
• Magnetospheric Accretion and Ejection of Matter in Resistive Magnetohydrodynamic Simulations
• Towards a New Standard Theory for Astrophysical Disk Accretion
• Resistive jet simulations extending radially self-similar magnetohydrodynamic models
• Global multifluid simulations of the magnetorotational instability in radially stratified protoplanetary disks
• Global Self-Similar Protostellar Disk/Wind Models
• Chemistry During the Gas-rich Stage of Planet Formation
• A wind-driving disc model for the mm-wavelength polarization structure of HL Tau
• Direct time radio variability induced by non-axisymmetric standing accretion shock instability: implications for M87
• Structure of Protoplanetary Discs with Magnetically-driven Winds
• On the appearance of non-local MRI in Keplerian accretion discs
• Formation of stars and planets: the role of magnetic fields
• Radial and vertical angular momentum transport in protostellar discs
• Type I Planet Migration in a Magnetized Disk. II. Effect of Vertical Angular Momentum Transport
• The role of magnetic fields in star formation
• Magnetic field gradient effects on the magnetorotational instability