Shock interactions, turbulence and the origin of the stellar mass spectrum
Shock interactions, turbulence and the origin of the stellar mass spectrum
复制标题
冲击相互作用、湍流和恒星质谱的起源
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
N. Kevlahan
中科院分区：
文献类型：
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作者：
R. Pudritz;N. Kevlahan
超音速湍流是理解星际气体内部结构如何产生和形成的基本要素。在星星形成的背景下，许多计算研究表明，致密云内密度和速度波动的质谱，以及它们的角动量分布，可以追溯到受到冲击波冲击的气体的统计和物理性质。在本文中，我们回顾了观察，模拟和理论如何类似的过程可以解释我们在分子云中看到的结构。然后，我们比较传统的超音速湍流的想法与一个简单的物理模型，涉及多个冲击波的影响和它们在星际介质中的相互作用。平面相交的激波产生密集的细丝，并产生涡面，这些涡面是在云中产生大范围密度和速度结构所必需的。作为一个例子，恒星初始质量函数的低质量行为可以追溯到冲击波集合建立对数正态密度分布（或柱密度）的趋势。涡是在激波云中产生很宽的长度尺度范围内的速度结构所必不可少的，也可以由弯曲激波或相交的平面激波通过这种介质而产生。另外两个主要的物理力影响着恒星形成气体的结构--引力和来自年轻恒星的反馈过程。这两种方法都可以在初始质量函数的高质量端产生幂律尾。
Supersonic turbulence is an essential element in understanding how structure within interstellar gas is created and shaped. In the context of star formation, many computational studies show that the mass spectrum of density and velocity fluctuations within dense clouds, as well as the distribution of their angular momenta, trace their origin to the statistical and physical properties of gas that is lashed with shock waves. In this paper, we review the observations, simulations and theories of how turbulent-like processes can account for the structures we see in molecular clouds. We then compare traditional ideas of supersonic turbulence with a simpler physical model involving the effects of multiple shock waves and their interactions in the interstellar medium. Planar intersecting shock waves produce dense filaments and generate vortex sheets that are essential to create the broad range of density and velocity structure in clouds. As an example, the lower-mass behaviour of the stellar initial mass function can be traced to the tendency of a collection of shock waves to build up a lognormal density distribution (or column density). Vorticity—which is essential to produce velocity structure over a very broad range of length scales in shocked clouds—can also be generated by the passage of curved shocks or intersecting planar shocks through such media. Two major additional physical forces affect the structure of star-forming gas—gravity and feedback processes from young stars. Both of these can produce power-law tails at the high-mass end of the initial mass function.
DOI：
10.1088/0004-6256/136/3/919
发表时间：
2005-06
期刊：
The Astronomical Journal
影响因子：
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作者：
M. Meixner;K. Gordon;R. Indebetouw;J. Hora;B. Whitney;R. Blum;W. Reach;J. Bernard;M. Meade;B. Babler;C. Engelbracht;B. For;K. Misselt;U. Vijh;C. Leitherer;M. Cohen;E. Churchwell;F. Boulanger;J. Frogel;Y. Fukui;J. Gallagher;V. Gorjian;J. Harris;D. Kelly;A. Kawamura;Soyoung Kim;W. Latter;S. Madden;Ciska Markwick-Kemper;A. Mizuno;N. Mizuno;J. Mould;A. Nota;M. Oey;K. Olsen;T. Onishi;R. Paladini;N. Panagia;P. Pérez-González;H. Shibai;Sato Shuji;Linda J. Smith;L. Staveley-Smith;A. Tielens;T. Ueta;S. V. Dyk;K. Volk;M. Werner;D. Zaritsky
通讯作者：
M. Meixner;K. Gordon;R. Indebetouw;J. Hora;B. Whitney;R. Blum;W. Reach;J. Bernard;M. Meade;B. Babler;C. Engelbracht;B. For;K. Misselt;U. Vijh;C. Leitherer;M. Cohen;E. Churchwell;F. Boulanger;J. Frogel;Y. Fukui;J. Gallagher;V. Gorjian;J. Harris;D. Kelly;A. Kawamura;Soyoung Kim;W. Latter;S. Madden;Ciska Markwick-Kemper;A. Mizuno;N. Mizuno;J. Mould;A. Nota;M. Oey;K. Olsen;T. Onishi;R. Paladini;N. Panagia;P. Pérez-González;H. Shibai;Sato Shuji;Linda J. Smith;L. Staveley-Smith;A. Tielens;T. Ueta;S. V. Dyk;K. Volk;M. Werner;D. Zaritsky