Protoplanetary migration in non-isothermal discs with turbulence driven by stochastic forcing

Abstract

Low-mass objects embedded in isothermal protoplanetary discs are known to suffer rapid inward Type I migration. In non-isothermal discs, recent work has shown that a decreasing radial profile of the disc entropy can lead to a strong positive corotation torque which can significantly slow down or reverse Type I migration in laminar viscous disc models. It is not clear however how this picture changes in turbulent disc models. The aim of this study is to examine the impact of turbulence on the torque experienced by a low-mass planet embedded in a non-isothermal protoplanetary disc. We particularly focus on the role of turbulence on the corotation torque whose amplitude depends on the efficiency of diffusion processes in the planet's horseshoe region. We performed 2D numerical simulations using a grid-based hydrodynamical code in which turbulence is modelled as stochastic forcing. In order to provide estimations for the viscous and thermal diffusion coefficients as a function of the amplitude of turbulence, we first set up non-isothermal disc models for different values of the amplitude of the turbulent forcing. We then include a low-mass planet and determine the evolution of its running time-averaged torque. We show that in non-isothermal discs, the entropy-related corotation torque can indeed remain unsaturated in the presence of turbulence. For turbulence amplitudes that do not strongly affect the disc temperature profile, we find that the running time-averaged torque experienced by an embedded protoplanet is in fairly good agreement with laminar disc models with appropriate values for the thermal and viscous diffusion coefficients. In discs with turbulence driven by stochastic forcing, the corotation torque therefore behaves similarly as in laminar viscous discs and can be responsible for significantly slowing down or reversing Type I migration.

accepted for publication in MNRAS

References in corpus (11)

• The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
• A comparative study of disc-planet interaction
• Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line
• On the corotation torque in a radiatively inefficient disk
• On corotation torques, horseshoe drag and the possibility of sustained stalled or outward protoplanetary migration
• Global MHD simulations of stratified and turbulent protoplanetary discs. I. Model properties
• On disc protoplanet interactions in a non-barotropic disc with thermal diffusion
• Global MHD simulations of stratified and turbulent protoplanetary discs. II. Dust settling
• Accretion of Terrestrial Planets from Oligarchs in a Turbulent Disk
• Saturated torque formula for planetary migration in viscous disks with thermal diffusion: recipe for protoplanet population synthesis
• 3D MHD Simulations of Planet Migration in Turbulent Stratified Disks

Cited by in corpus (11)

• Breaking the Chains: Hot Super-Earth systems from migration and disruption of compact resonant chains
• Effects of the Planetary Temperature on the Circumplanetary Disk and on the Gap
• Planet formation in Binaries
• Type I planet migration in weakly magnetised laminar discs
• Convergence zones for Type I migration: an inward shift for multiple planet systems
• Fast migration of low-mass planets in radiative discs
• Understanding the assembly of Kepler's compact planetary systems
• Thermodynamics of the dead-zone inner edge in protoplanetary disks
• Making giant planet cores: convergent migration and growth of planetary embryos in non-isothermal discs
• Photoevaporation Does Not Create a Pileup of Giant Planets at 1 AU
• Insights from Analytical Theory of Eccentric Circumbinary Disks