论文标题
条纹，积分，沙漏和塌陷 - 分子云的热不稳定性磁模拟
Striations, integrals, hourglasses and collapse -- thermal instability driven magnetic simulations of molecular clouds
论文作者
论文摘要
通过3D模拟在几个parsecs的尺度上形成崩溃的冷团，在较大的分子云中，使用3D模拟，在3D模拟中，使用3D模拟，在3D模拟中，使用了自适应网格改进（AMR）代码（AMR）代码的MHD版本。弥漫性原子初始条件由固定的，热不稳定的球形云组成，在压力平衡中，周围密度较低，并由均匀的磁场螺纹组成。该云在n = 1.1 cm^{ - 3}左右的最佳初始网格水平下用10％密度扰动播种，并从一开始就随着自我重力而演变。考虑了几个云直径（100 PC，200 PC和400 PC），等于几个云质量（17,000 MSUN，136,000 MSUN和1.1x10^6 MSUN）。当云层沿田间线塌陷成圆盘状结构时，观察到低密度磁场对齐的条纹。沿场线的诱导流动导致板的振荡在重力最小值和整体形外观上。当磁性超临界时，云会崩溃并产生具有强烈加强磁场的沙漏磁场构型，从而再现观测行为。在较高分辨率下的最高质量云区域的重复模拟形成了包含块状框架超音速（M〜5）和超级alfentic（M_A〜4）速度的纸板内的重力崩溃的团块。获得了云和最密集团的观察逼真的密度和速度功率谱。未来的工作将利用这些现实的初始条件来研究单个星星和聚类反馈。
The MHD version of the adaptive mesh refinement (AMR) code, MG, has been employed to study the interaction of thermal instability, magnetic fields and gravity through 3D simulations of the formation of collapsing cold clumps on the scale of a few parsecs, inside a larger molecular cloud. The diffuse atomic initial condition consists of a stationary, thermally unstable, spherical cloud in pressure equilibrium with lower density surroundings and threaded by a uniform magnetic field. This cloud was seeded with 10% density perturbations at the finest initial grid level around n=1.1 cm^{-3} and evolved with self-gravity included from the outset. Several cloud diameters were considered (100 pc, 200 pc and 400 pc) equating to several cloud masses (17,000 Msun, 136,000 Msun and 1.1x10^6 Msun). Low-density magnetic-field-aligned striations were observed as the clouds collapse along the field lines into disc-like structures. The induced flow along field lines leads to oscillations of the sheet about the gravitational minimum and an integral-shaped appearance. When magnetically supercritical, the clouds then collapse and generate hourglass magnetic field configurations with strongly intensified magnetic fields, reproducing observational behaviour. Resimulation of a region of the highest mass cloud at higher resolution forms gravitationally-bound collapsing clumps within the sheet that contain clump-frame supersonic (M~5) and super-Alfvenic (M_A~4) velocities. Observationally realistic density and velocity power spectra of the cloud and densest clump are obtained. Future work will use these realistic initial conditions to study individual star and cluster feedback.
