Global simulations of self-gravitating magnetized protoplanetary disks

Abstract

In the early stages of a protoplanetary disk, when its mass is a significant fraction of its star's, turbulence generated by gravitational instability (GI) should feature significantly in the disk's evolution. At the same time, the disk may be sufficiently ionised for magnetic fields to play some role in the dynamics. Though usually neglected, the impact of magnetism on the GI may be critical, with consequences for several processes: the efficiency of accretion, spiral structure formation, fragmentation, and the dynamics of solids. In this paper, we report on global three-dimensional magnetohydrodynamical simulations of a self-gravitating protoplanetary disk using the meshless finite mass (MFM) Lagrangian technique. We confirm that GI spiral waves trigger a dynamo that amplifies an initial magnetic field to nearly thermal amplitudes (plasma beta < 10), an order of magnitude greater than that generated by the magneto-rotational instability alone. We also determine the dynamo's nonlinear back reaction on the gravitoturbulent flow: the saturated state is substantially hotter, with an associated larger Toomre parameter and weaker, more 'flocculent' spirals. But perhaps of greater import is the dynamo's boosting of accretion via a significant Maxwell stress; mass accretion is enhanced by factors of several relative to either pure GI or pure MRI. Our simulations use ideal MHD, an admittedly poor approximation in protoplanetary disks, and thus future studies should explore the full gamut of non-ideal MHD. In preparation for that, we exhibit a small number of Ohmic runs that reveal that the dynamo, if anything, is stronger in a non-ideal environment. This work confirms that magnetic fields are a potentially critical ingredient in gravitoturbulent young disks, possibly controlling their evolution, especially via their enhancement of (potentially episodic) accretion.

Happy Chinese new year

References in corpus (29)

• Spiral Density Waves in a Young Protoplanetary Disk
• On the diversity and statistical properties of protostellar discs
• Global simulations of protoplanetary disks with ohmic resistivity and ambipolar diffusion
• The Two Modes of Gas Giant Planet Formation
• Magnetic fields in protoplanetary disks
• Characterising the Gravitational Instability in Cooling Accretion Discs
• Variable protostellar accretion with episodic bursts
• Fragmentation of gravitationally unstable gaseous protoplanetary disks with radiative transfer
• The Disk Substructures at High Angular Resolution Project (DSHARP): III. Spiral Structures in the Millimeter Continuum of the Elias 27, IM Lup, and WaOph 6 Disks
• The Thermal Regulation of Gravitational Instabilities in Protoplanetary Disks III. Simulations with Radiative Cooling and Realistic Opacities
• Global MHD simulations of stratified and turbulent protoplanetary discs. I. Model properties
• Numerical requirements for simulations of self gravitating and non-self gravitating disks
• Spatially Resolved Magnetic Field Structure in the Disk of a T Tauri Star
• The Mass Budget of Planet Forming Discs: Isolating the Epoch of Planetesimal Formation
• Grand Design Spiral Arms in A Young Forming Circumstellar Disk
• On Self-Sustained Dynamo Cycles in Accretion Discs
• The role of magnetic fields in the formation of protostellar discs
• Convergence of the critical cooling rate for protoplanetary disk fragmentation achieved; the key role of numerical dissipation of angular momentum
• Stringent limits on the magnetic field strength in the disc of TW Hya: ALMA observations of CN polarisation
• Circumplanetary disks around young giant planets: a comparison between core-accretion and disk instability
• Gravito-Turbulent Disks in 3D: Turbulent Velocities vs. Depth
• Disk Formation in Magnetized Dense Cores with Turbulence and Ambipolar Diffusion
• Magnetorotational instability and dynamo action in gravitoturbulent astrophysical discs
• Characterizing gravito-turbulence in 3D: turbulent properties and stability against fragmentation
• Magnetic fields in circumstellar disks: The potential of Zeeman observations
• On the fragmentation boundary in magnetised self-gravitating discs
• Local simulations of MRI turbulence with meshless methods
• A New Public Release of the GIZMO Code
• Protoplanetary disk fragmentation with varying radiative physics, initial conditions and numerical techniques

Cited by in corpus (25)

• In-situ extreme mass ratio inspirals via sub-parsec formation and migration of stars in thin, gravitationally unstable AGN discs
• 3D Radiation Hydrodynamic Simulations of Gravitational Instability in AGN Accretion Disks: Effects of Radiation Pressure
• Formation of intermediate-mass planets via magnetically-controlled disk fragmentation
• Rimmed and Rippled Accretion Disc Models to Explain AGN Continuum Lags
• Chaotic Type I Migration in Turbulent Discs
• The influence of infall on the properties of protoplanetary discs
• Spiral structures in gravito-turbulent gaseous disks
• Chaotic Gas Accretion by Black Holes Embedded in AGN Discs as Cause of Low-spin Signatures in Gravitational Wave Events
• Parametric instability in a free evolving warped protoplanetary disc
• Magnetorotational instability with smoothed particle hydrodynamics
• Simulating the magnetorotational instability on a moving mesh with the shearing box approximation
• A scalable elliptic solver with task-based parallelism for the SpECTRE numerical relativity code
• Presolar grain dynamics: creating nucleosynthetic variations through a combination of drag and viscous evolution
• Characterizing fragmentation and sub-Jovian clump properties in magnetized young protoplanetary disks
• Formation of low mass protostars and their circumstellar disks
• Simulating cold shear flows on a moving mesh
• Eruptive Behavior of Magnetically Layered Protoplanetary Disks in Low Metallicity Environments
• Turbulent Transport of Dust Particles in Protostellar Disks: The Effect of Upstream Diffusion
• Birth of magnetized low-mass protostars and circumstellar disks
• Giant planets population around B stars from the first part of the BEAST survey
• DIPSY: A new Disc Instability Population SYnthesis, II. The Populations of Companions Formed Through Disc Instability
• Gravito-turbulence and dynamo in poorly ionised protostellar discs. I. Zero-net-flux case
• An efficient spectral Poisson solver for the nirvana-III code: the shearing-box case with vertical vacuum boundary conditions
• Gravitoturbulent dynamo in global simulations of gaseous disks
• A novel sub-grid model for super-Eddington accretion of spinning black holes in galaxy-scale simulations