Low mass planets in protoplanetary disks with net vertical magnetic fields: the Planetary Wake and Gap Opening

Abstract

We study wakes and gap opening by low mass planets in gaseous protoplanetary disks threaded by net vertical magnetic fields which drive magnetohydrodynamical (MHD) turbulence through the magnetorotational instabilty (MRI), using three dimensional simulations in the unstratified local shearing box approximation. The wakes, which are excited by the planets, are damped by shocks similar to the wake damping in inviscid hydrodynamic (HD) disks. Angular momentum deposition by shock damping opens gaps in both MHD turbulent disks and inviscid HD disks even for low mass planets, in contradiction to the "thermal criterion" for gap opening. To test the "viscous criterion", we compared gap properties in MRI-turbulent disks to those in viscous HD disks having the same stress, and found that the same mass planet opens a significantly deeper and wider gap in net vertical flux MHD disks than in viscous HD disks. This difference arises due to the efficient magnetic field transport into the gap region in MRI disks, leading to a larger effective αwithin the gap. Thus, across the gap, the Maxwell stress profile is smoother than the gap density profile, and a deeper gap is needed for the Maxwell stress gradient to balance the planetary torque density. We also confirmed the large excess torque close to the planet in MHD disks, and found that long-lived density features (termed zonal flows) produced by the MRI can affect planet migration. The comparison with previous results from net toroidal flux/zero flux MHD simulations indicates that the magnetic field geometry plays an important role in the gap opening process. Overall, our results suggest that gaps can be commonly produced by low mass planets in realistic protoplanetary disks, and caution the use of a constant α-viscosity to model gaps in protoplanetary disks.

Accepted by ApJ, 23 pages, 13 figures. Movie at http://www.astro.princeton.edu/~zhzhu/Site/Movies5.html

References in corpus (17)

• Athena: A New Code for Astrophysical MHD
• A comparative study of disc-planet interaction
• Local Study of Accretion Disks with a Strong Vertical Magnetic Field: Magnetorotational Instability and Disk Outflow
• Impact of dimensionless numbers on the efficiency of MRI-induced turbulent transport
• MHD simulations of the magnetorotational instability in a shearing box with zero net flux. I. The issue of convergence
• Vortex generation in protoplanetary disks with an embedded giant planet
• Global MHD simulations of stratified and turbulent protoplanetary discs. I. Model properties
• Local outflows from turbulent accretion disks
• Type I Planet Migration in Nearly Laminar Disks
• The magnetorotational instability as a jet launching mechanism
• 3D MHD Simulations of Planet Migration in Turbulent Stratified Disks
• Simulations of Magnetorotational Turbulence with a Higher-Order Godunov Scheme
• Type I planet migration in weakly magnetised laminar discs
• Orbital Advection by Interpolation: A Fast and Accurate Numerical Scheme for Super-Fast MHD Flows
• Type III migration in a low viscosity disc
• Low-mass planets in nearly inviscid disks: Numerical treatment
• The Effect of Poloidal Magnetic Field on Type I Planetary Migration: Significance of Magnetic Resonance

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