The onset of collapse in turbulently supported molecular clouds
The onset of collapse in turbulently supported molecular clouds
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湍流支撑的分子云开始塌陷
DOI：
10.1111/j.1365-2966.2005.09105.x
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发表时间：
2005
影响因子：
4.8
通讯作者：
I. Bonnell
中科院分区：
文献类型：
--
作者：
P. Clark;I. Bonnell
我们研究了湍流分子云的环境中形成的束缚相干团块，重点是确定湍流运动在星星形成过程中发挥的作用。我们使用光滑粒子流体动力学来模拟小分子云（1030 M），其中气体最初由自由衰减的湍流场从引力坍缩中支持，与σ <$L1/2的Larson关系一致。我们表明，湍流场不触发星星形成通过本地减少的牛仔裤质量，已提出在文献中的其他地方。相反，湍流的作用只是提供冲击，消散支撑动能并产生结构，作为随后碎裂的种子。这些结构最初是不受约束的，但通过较大尺度区域的自引力而生长。一旦它们达到云的平均金斯质量，崩溃就开始了。在这一点上，它们的动能和热能近似均分，因此在坍缩过程中可以分裂形成一个多重系统。因此，多重系统是星星在湍流环境中形成的自然结果。
We examine the formation of bound coherent clumps within the environment of turbulent molecular clouds, with emphasis on determining the role that turbulent motions play in the star formation process. We use smoothed particle hydrodynamics to simulate small molecular clouds (∼30 M⊙), in which the gas is initially supported from gravitational collapse by a freely decaying turbulent field, consistent with a Larson relation of σ ∝ L1/2. We show that the turbulent field does not trigger the star formation via local decreases in the Jeans mass, as has been proposed elsewhere in the literature. Instead, the role of the turbulence is simply to provide shocks that dissipate the supporting kinetic energy and generate structure which acts as seeds for the subsequent fragmentation. These structures are initially unbound, but grow through the self-gravity of the larger-scale region. Collapse proceeds once they attain the mean Jeans mass of the cloud. At this point they are in approximate equipartition of kinetic and thermal energies and can thus fragment to form a multiple system during collapse. Multiple systems are thus a natural consequence of star formation in a turbulent environment.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell