Implementation of dust particles in three-dimensional magnetohydrodynamics simulation: dust dynamics in a collapsing cloud core
Implementation of dust particles in three-dimensional magnetohydrodynamics simulation: dust dynamics in a collapsing cloud core
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尘埃颗粒在三维磁流体动力学模拟中的实现：塌陷云核中的尘埃动力学
DOI：
10.1093/mnras/stac2115
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发表时间：
2022
影响因子：
4.8
通讯作者：
Machida Masahiro N
中科院分区：
文献类型：
--
作者：
Koga Shunta;Kawasaki Yoshihiro;Machida Masahiro N
本研究的目的是在大尺度上研究尘埃动力学，并探讨在星星形成过程中尘埃与气体流体的耦合。本文提出了一种计算引力坍缩云中尘埃运动轨迹的方法，其中尘埃颗粒被视为拉格朗日粒子，并假定是中性的。我们结合非理想磁流体动力学模拟进行尘埃轨迹计算。我们的模拟表明，大小为的尘埃颗粒与恒星形成云核中的气体耦合。我们研究了尘埃-气体质量比和斯托克斯数的时间演化，斯托克斯数被定义为由自由落体时间尺度归一化的停止时间，并表明大尘埃颗粒（）具有大的斯托克斯数（接近1），并且倾向于比小颗粒（）更快地集中在中心区域（即原恒星和旋转支撑盘）。因此，大颗粒显著增加了盘周围和内部的灰尘与气体的质量比。我们还确认，尘埃轨迹的计算，跟踪每个尘埃粒子的物理量，再现以前报道的结果使用欧拉方法。
The aim of this study is to examine dust dynamics on a large scale and investigate the coupling of dust with gas fluid in the star formation process. We propose a method for calculating the dust trajectory in a gravitationally collapsing cloud, where the dust grains are treated as Lagrangian particles and are assumed to be neutral. We perform the dust trajectory calculations in combination with non-ideal magnetohydrodynamics simulation. Our simulation shows that dust particles with a size ofare coupled with gas in a star-forming cloud core. We investigate the time evolution of the dust-to-gas mass ratio and the Stokes number, which is defined as the stopping time normalized by the freefall time-scale, and show that large dust grains () have a large Stokes number (close to unity) and tend to concentrate in the central region (i.e. protostar and rotationally supported disc) faster than do small grains (). Thus, large grains significantly increase the dust-to-gas mass ratio around and inside the disc. We also confirm that the dust trajectory calculations, which trace the physical quantities of each dust particle, reproduce previously reported results obtained using the Eulerian approach.