Turbulent Transport of Dust Particles in Protostellar Disks: The Effect of Upstream Diffusion

Abstract

We study the long-term radial transport of micron to mm-size grain in protostellar disks (PSDs) based on diffusion and viscosity coefficients measured from 3D global stratified-disk simulations with a Lagrangian hydrodynamic method. While gas-drag tend to transport dust species radially inwards, stochastic diffusion can spread a considerable fraction of dust radially outwards (upstream) depending on the nature of turbulence. In gravitationally unstable disks, we measure a high radial diffusion coefficient Dr with little dependence on altitude. This leads to strong and vertically homogeneous upstream diffusion in early PSDs. In the solar nebula, the robust upstream diffusion of micron to mm size grains not only efficiently transports highly refractory mocron-size grains (such as those identified in the samples of comet 81P/Wild 2) from their regions of formation inside the snow line out to the Kuiper Belt, but can also spread mm-size CAI formed in the stellar proximity to distances where they can be assimilated into chondritic meteorites. In disks dominated by magnetorotational instability (MRI), the upstream diffusion effect is generally milder, with a separating feature due to diffusion being stronger in the surface layer than the midplane. This variation becomes much more pronounced if we additionally consider a quiescent midplane with lower turbulence and larger characteristic dust size due to non-ideal MHD effects. This segregation scenario helps to account for dichotomy of two dust populations' spatial distribution as observed in scattered light and ALMA images.

ApJ published, 14 pages, 12 figures

References in corpus (22)

• Gas- and dust evolution in protoplanetary disks
• Particle Stirring in Turbulent Gas Disks: Including Orbital Oscillations
• Closed-form expressions for particle relative velocities induced by turbulence
• Analytical protostellar disk models 1: the effect of internal dissipation and surface irradiation on the structure of disks and the location of the snow line around Sun-like stars
• Observations of edge-on protoplanetary disks with ALMA I. Results from continuum data
• Global Simulations of the Inner Regions of Protoplanetary Disks with Comprehensive Disk Microphysics
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• Ring formation and dust dynamics in wind-driven protoplanetary discs: global simulations
• Convergence of the critical cooling rate for protoplanetary disk fragmentation achieved; the key role of numerical dissipation of angular momentum
• Dust Transport in MRI Turbulent Disks: Ideal and Non-ideal MHD with Ambipolar Diffusion
• Global simulations of self-gravitating magnetized protoplanetary disks
• Formation of intermediate-mass planets via magnetically-controlled disk fragmentation
• The Preservation of Super Earths and the Emergence of Gas Giants after Their Progenitor Cores have Entered the Pebble Isolation Phase
• Testing a New Model of Embedded Protostellar Disks Against Observation: The Majority of Orion Class 0/I Disks Are Likely Warm, Massive, and Gravitationally Unstable
• Spiral structures in gravito-turbulent gaseous disks
• Local simulations of MRI turbulence with meshless methods
• Effects of Ringed Structures and Dust Size Growth on Millimeter Observations of Protoplanetary Disks
• Particle Dynamics in 3D Self-gravitating Disks II: Strong Gas Accretion and Thin Dust Disks
• Dust dynamics and vertical settling in gravitoturbulent protoplanetary discs
• Magnetorotational instability with smoothed particle hydrodynamics
• Wide Dust Gaps in Protoplanetary Disks Induced by Eccentric Planets: A Mass-Eccentricity Degeneracy
• Dust Transport in Protoplanetary Disks with Wind-driven Accretion

Cited by in corpus (3)

• Distinguishing Magnetized Disc Winds from Turbulent Viscosity through Substructure Morphology in Planet-forming Discs
• Planetesimal Growth in Evolving Protoplanetary Disks: Constraints from the Pebble Supply
• Effects of Stellar X-ray Photoevaporation on Planetesimal Formation via the Streaming Instability