Effective dust growth in laminar circumplanetary discs with magnetic wind-driven accretion
Effective dust growth in laminar circumplanetary discs with magnetic wind-driven accretion
复制标题
磁风驱动吸积作用下层流环行星盘中尘埃的有效生长
DOI：
10.1093/mnras/stac3428
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发表时间：
2022
影响因子：
4.8
通讯作者：
Mori Shoji
中科院分区：
文献类型：
--
作者：
Shibaike Yuhito;Mori Shoji
人们认为，气体行星周围的大型卫星形成原位环绕行星盘（CPD）。然而，供给 CPD 的尘埃颗粒在成长为小卫星（卫星的组成部分）之前会向中心行星漂移。我们研究了磁风驱动吸积层流 CPD 中灰尘的生长。在这种层流盘中，灰尘颗粒可以沉积在中平面上，并通过相互碰撞而变大，这比经典的湍流 CPD 更有效。首先，我们对 CPD 进行 3D 局部 MHD 模拟，包括所有非理想 MHD 效应（欧姆电阻率、霍尔效应和双极扩散）。我们研究了盘吸积是否可以由磁风驱动吸积控制，以及在磁盘风可以从盘中发射的情况下，盘的层流程度如何。其次，我们对与 MHD 模拟结果一致的一维稳态 CPD 进行建模，并计算建模盘中尘埃轮廓的稳态径向分布，同时考虑开尔文-亥姆霍兹不稳定性引起的碰撞生长、径向漂移、破碎和垂直搅拌。我们表明，如果流入圆盘的尘埃与气体质量比大于 0.02（比湍流 CPD 中的临界值小 50 倍），则在此类 CPD 中会形成卫星。当足够多的尘埃堆积在行星产生的气体压力波动处时，这个条件就可以满足。这一结果表明，小卫星将在具有磁风驱动吸积作用的层流 CPD 中形成。
It has been considered that large satellites around gas planets formin situcircumplanetary discs (CPDs). However, dust particles supplied into CPDs drift toward the central planets before they grow into satellitesimals, building blocks of the satellites. We investigate the dust growth in laminar CPDs with magnetic wind-driven accretion. In such laminar discs, dust particles can settle on to the mid-plane and grow large by mutual collision more efficient than in classical turbulent CPDs. First, we carry out 3D local MHD simulations of a CPD including all the non-ideal MHD effects (Ohmic resistivity, Hall effect, and ambipolar diffusion). We investigate if the disc accretion can be governed by magnetic wind-driven accretion and how laminar the disc can be, in a situation where the magnetic disc wind can be launched from the disc. Secondly, we model 1D steady CPDs consistent with the results of the MHD simulations and calculate the steady radial distributions of the dust profiles in the modelled discs, taking account of the collisional growth, radial drift, fragmentation, and vertical stirring by the Kelvin–Helmholtz instability. We show that satellitesimals can form in such CPDs if the dust-to-gas mass ratio of the inflow to the discs is larger than 0.02, which is 50 times smaller than the critical value in turbulent CPDs. This condition can be satisfied when enough amount of dust piles up at the gas pressure bump created by the planets. This result shows that satellitesimals would form in laminar CPDs with magnetic wind-driven accretion.