The Turbulent Interstellar Medium: Insights and Questions from Numerical Models
The Turbulent Interstellar Medium: Insights and Questions from Numerical Models
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湍流的星际介质：数值模型的见解和问题
DOI：
10.1007/1-4020-2620-x_69
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
M. Korpi
中科院分区：
文献类型：
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作者：
M. M. Low;M. D. Avillez;M. Korpi
“数值模型的目的不是数字，而是洞察。”（汉明）本着这句格言的精神，以及唐·考克斯的科学演讲方式，我们讨论了最新一代星际介质数值模型提出的问题，至少对我们来说是这样。星际湍流的能量来源仍在讨论中。我们回顾了超新星在恒星形成区域占主导地位的论点。磁旋不稳定性被认为是圆盘剪切与湍流耦合的一种方式。模型清楚地表明，与热不稳定波长相比，不稳定波长非常长，这意味着外星系和低表面亮度盘的恒星形成。在sn驱动的介质中，决定热气体填充因子的因素仍然是一个长期存在的问题，特别是因为在模型中看到的热腔边界出现了意想不到的强烈湍流混合。湍流中分子云的形成也知之甚少。适合云形成的密集区域即使在没有自重力的情况下也能明显形成，尽管它们的最终演化仍有待计算。
“The purpose of numerical models is not numbers but insight.” (Hamming) In the spirit of this adage, and of Don Cox’s approach to scientific speaking, we discuss the questions that the latest generation of numerical models of the interstellar medium raise, at least for us. The energy source for the interstellar turbulence is still under discussion. We review the argument for supernovae dominating in star forming regions. Magnetorotational instability has been suggested as a way of coupling disk shear to the turbulent flow. Models make evident that the unstable wavelengths are very long compared to thermally unstable wavelengths, with implications for star formation in the outer galaxy and low surface brightness disks. The perennial question of the factors determining the hot gas filling factor in a SN-driven medium remains open, in particular because of the unexpectedly strong turbulent mixing at the boundaries of hot cavities seen in the models. The formation of molecular clouds in the turbulent flow is also poorly understood. Dense regions suitable for cloud formation clearly form even in the absence of self-gravity, although their ultimate evolution remains to be computed.