Nonideal MHD Simulation of HL Tau Disk: Formation of Rings
Nonideal MHD Simulation of HL Tau Disk: Formation of Rings
复制标题
DOI：
10.3847/1538-4357/ab44cb
复制
发表时间：
2019-04
期刊：
影响因子：
--
通讯作者：
X. Hu 胡;Z. Zhu 朱;S. Okuzumi 奥;X. Bai 白;L. Wang 王;Kengo 田賢吾 Tomida 富;J. Stone
中科院分区：
文献类型：
--
作者：
X. Hu 胡;Z. Zhu 朱;S. Okuzumi 奥;X. Bai 白;L. Wang 王;Kengo 田賢吾 Tomida 富;J. Stone
最近的高分辨率观测揭示了星周盘的环状结构。这些环的起源已经在各种理论情景下得到了广泛的研究。在这项工作中，我们进行了全球三维非理想MHD模拟，包括欧姆电阻率和双极扩散（AD）的影响，以模拟HL Tau盘。基于考虑烧结效应的全局粉尘演化计算，计算了非理想MHD扩散曲线。由于主要挥发物雪线附近粉尘粒径分布的变化，使得圆盘电离结构在雪线上发生了显著变化。我们发现吸积主要是由盘风驱动的。雪线上不同的吸积速率可以迅速产生缝隙和环。此外，AD会导致中间高度优先的吸积，然后是磁重联。这就产生了一个局部的排泄区，该排泄区在场重连接区域内排出物质，从而在其外部留下一个间隙和一个相邻的环。总的来说，在有利的条件下，雪线和非理想的MHD效应都可以导致原行星盘中的气体间隙和环。
Recent high-resolution observations unveil ring structures in circumstellar disks. The origin of these rings has been widely investigated under various theoretical scenarios. In this work we perform global 3D nonideal MHD simulations including effects from both ohmic resistivity and ambipolar diffusion (AD) to model the HL Tau disk. The nonideal MHD diffusion profiles are calculated based on the global dust evolution calculation including sintering effects. Disk ionization structure changes dramatically across the snow line due to the change of dust size distribution close to the snow line of major volatiles. We find that accretion is mainly driven by disk wind. Gaps and rings can be quickly produced from different accretion rates across the snow line. Furthermore, AD leads to highly preferential accretion at the midplane, followed by magnetic reconnection. This results in a local zone of decretion that drains the mass in the field reconnection area, which leaves a gap and an adjacent ring just outside of it. Overall, under favorable conditions, both snow lines and nonideal MHD effects can lead to gaseous gaps and rings in protoplanetary disks.