The Formation of Self-Gravitating Cores in Turbulent Magnetized Clouds
The Formation of Self-Gravitating Cores in Turbulent Magnetized Clouds
复制标题
湍流磁化云中自引力核心的形成
DOI：
10.1086/382652
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
F. Heitsch
中科院分区：
文献类型：
--
作者：
P. Li;M. Norman;M. Mac Low;F. Heitsch
我们使用ZEUS-MP进行高分辨率，三维，super-Alfvénic湍流模拟，以研究磁场在湍流分子云中自引力核形成中的作用。我们的super-Alfvénic模型的统计特性没有重力同意以前的类似研究。包括自引力，我们的模型给出了以下结果。它们与Padoan & Nordlund的核心质量分布的湍流破碎预测是一致的。他们还证实，局部引力坍缩并没有阻止由湍流驱动的磁流体动力学波，即使当湍流的牛仔裤质量超过模拟体积中的质量。2563和5123区域模拟结果的比较揭示了崩溃率的收敛。对模拟中形成的自引力核的分析表明：（1）形成的所有核都是磁超临界的，至少有一个数量级。(2)尽管堆芯处于强超临界状态，但中心磁场强度与密度Bc ρ之间仍存在幂律关系。(3)半径为R的核的比角动量j <$R3/2。(4)大多数岩心呈长球形和三轴形，与Gammie等人的结果一致。我们发现，在我们的模拟在晚些时候，核心的短轴和本地磁场之间的弱相关性，从Gammie和同事报告的不相关的结果不同。核心形状分析和核心质量与半径M <$R2.75之间的幂律关系表明形成了一些高度扁平的核心。在高分辨率模拟的后期阶段，我们确定了12个具有圆盘状外观的云核。而不是被潮汐截断或破坏，核心磁盘生存和蓬勃发展，同时经历强烈的相互作用。我们讨论了这些盘状核的物理性质下的分辨率限制的约束。
We use ZEUS-MP to perform high-resolution, three-dimensional, super-Alfvénic turbulent simulations in order to investigate the role of magnetic fields in self-gravitating core formation within turbulent molecular clouds. Statistical properties of our super-Alfvénic model without gravity agree with previous similar studies. Including self-gravity, our models give the following results. They are consistent with the turbulent fragmentation prediction of the core mass distribution of Padoan & Nordlund. They also confirm that local gravitational collapse is not prevented by magnetohydrodynamic waves driven by turbulent flows, even when the turbulent Jeans mass exceeds the mass in the simulation volume. Comparison of results between 2563 and 5123 zone simulations reveals convergence in the collapse rate. Analysis of self-gravitating cores formed in the simulation shows the following: (1) All cores formed are magnetically supercritical by at least an order of magnitude. (2) A power-law relation between central magnetic field strength and density Bc ∝ ρ is observed despite the cores being strongly supercritical. (3) Specific angular momentum j ∝ R3/2 for cores with radius R. (4) Most cores are prolate and triaxial in shape, in agreement with the results of Gammie and coworkers. We find a weak correlation between the minor axis of the core and the local magnetic field in our simulation at late times, different from the uncorrelated results reported by Gammie and coworkers. The core shape analysis and the power-law relationship between core mass and radius M ∝ R2.75 suggest the formation of some highly flattened cores. We identified 12 cloud cores with disklike appearance at a later stage of our high-resolution simulation. Instead of being tidally truncated or disrupted, the core disks survive and flourish while undergoing strong interactions. We discuss the physical properties of these disklike cores under the constraints of resolution limits.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell