PF-02-0027

Effects of magnetically driven disk winds on the gas surface density evolution and dust growth in protoplanetary disks

Tetsuo Taki, Hiroshi Kobayashi, Eiichirou Kokubo, Takeru K Suzuki

We investigate the effects of magnetically driven disk winds (MDWs) on the evolution of protoplanetary disks and the formation of planetesimals using a one-dimensional model.
We report on the characteristics of the gas surface density evolution and the radial profiles achieved under the MDWs.
The MDWs are an essential driver of protoplanetary disk evolution.
In the classical view, the gas surface density of protoplanetary disks evolves viscously.
Small-scale angular momentum transport by magnetohydrodynamic turbulence is macroscopically manifested as viscous evolution of the gas surface density.
However, the recent disk observations and non-ideal magnetohydrodynamic simulations revealed that the turbulence driven in the disk is likely not strong enough to ensure the disk evolution (e.g., Pinte et al. 2016; Bai 2017; Gressel et al. 2020).
The effects of the MDWs have different properties from those of viscous ones, and it has been found that the steady accretion and self-similar solutions are realized differently from viscous accretion disks (see also Chambers 2019; Tabone et al. 2021).
In such disks, there exists a new dust growth mode that is not found in classical viscous accretion disks (Taki et al. 2021).
The conditions for the growth mode can be formulated by a simple state consisting of the dust-gas surface density ratio and the dimensionless radial pressure gradient force of disk gas.
This mechanism tends to form a ring-shaped dust growth region in the inner part of the disk at a relatively early stage of disk evolution.
This process plays an important role in the formation process of planetary systems.

[Poster PDF File]