Streaming Torque with Turbulent Diffusion

Fuente: arXiv
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Main Authors: Hou, Qiang, Yu, Cong
Format: Preprint
Published: 2024
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_version_ 1866910750655643648
author Hou, Qiang
Yu, Cong
author_facet Hou, Qiang
Yu, Cong
contents Fast type-I migration of (proto)planets poses a challenging problem for the core accretion formation scenario. We found that the dust-induced ``Streaming Torque (ST)'' may slow down or even reverse the planet migration in \cite{Hou2024}. But in realistic protoplanetary disks, dust diffusion induced by gas turbulence may have important influences on ST. We perform linear analysis to investigate the effects of dust diffusion on ST. The dependence of ST on the dust diffusion may provide better constraints on the turbulence strength and the stopping time $τ$. We derive the dispersion relation for all the wave modes in the two-fluid system. The dust diffusion will smooth the short-wavelength structure of the the quasi-drift mode and split it into two predominant D-drift modes with opposite directions. The outgoing D-drift mode will contribute to a negative torque on planets, particularly when $τ\sim 0.1$, which slightly shifts the zero-torque turning point. We explore how ST depends on the regimes of aerodynamic drag, dust mass fraction and disk scale height. We compare the radial wavenumbers of D-drift modes under different formulations of dust diffusion and find qualitative agreement. In all cases, $τ$ at the zero-torque turning point, which determines the direction of planetary migration, consistently remains on the order of $\sim 0.1$, corresponding to large pebble-sized dust grains. This suggests that rapid dust coagulation can inhibit the inward migration of planets, implying that weak gas turbulence may enhance the survival of protoplanets.
format Preprint
id arxiv_https___arxiv_org_abs_2412_13448
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Streaming Torque with Turbulent Diffusion
Hou, Qiang
Yu, Cong
Earth and Planetary Astrophysics
Solar and Stellar Astrophysics
Fast type-I migration of (proto)planets poses a challenging problem for the core accretion formation scenario. We found that the dust-induced ``Streaming Torque (ST)'' may slow down or even reverse the planet migration in \cite{Hou2024}. But in realistic protoplanetary disks, dust diffusion induced by gas turbulence may have important influences on ST. We perform linear analysis to investigate the effects of dust diffusion on ST. The dependence of ST on the dust diffusion may provide better constraints on the turbulence strength and the stopping time $τ$. We derive the dispersion relation for all the wave modes in the two-fluid system. The dust diffusion will smooth the short-wavelength structure of the the quasi-drift mode and split it into two predominant D-drift modes with opposite directions. The outgoing D-drift mode will contribute to a negative torque on planets, particularly when $τ\sim 0.1$, which slightly shifts the zero-torque turning point. We explore how ST depends on the regimes of aerodynamic drag, dust mass fraction and disk scale height. We compare the radial wavenumbers of D-drift modes under different formulations of dust diffusion and find qualitative agreement. In all cases, $τ$ at the zero-torque turning point, which determines the direction of planetary migration, consistently remains on the order of $\sim 0.1$, corresponding to large pebble-sized dust grains. This suggests that rapid dust coagulation can inhibit the inward migration of planets, implying that weak gas turbulence may enhance the survival of protoplanets.
title Streaming Torque with Turbulent Diffusion
topic Earth and Planetary Astrophysics
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2412.13448