Large-Scale Turbulence in Molecular Clouds
Large-Scale Turbulence in Molecular Clouds
复制标题
分子云中的大规模湍流
DOI：
10.1086/345294
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
C. Brunt
中科院分区：
文献类型：
--
作者：
C. Brunt
本文利用12 CO（J = 1-0）辐射的主成分分析来诊断分子云中是否存在大尺度的、全球性的速度起伏。我们寻找并发现了大规模的原子物质流，其中嵌入了全球动荡的分子云。这与分子云在大尺度原子流中作为短暂的湍流密度波动存在的图像是一致的。大规模的驱动湍流的分子云中，通过会聚流动的原子材料，可以调和最近的数值测定的湍流能量的耗散率与观测，否则，小规模的驱动，导致不可接受的高云光度。另一方面，缺乏大规模的冲击签名的分子气体，预期大规模的驱动，可能，如果不是由于观测偏差，需要大规模的流动本身驱动的能量注入发生在较小的尺度内的分子云。
Principal component analysis of 12CO (J = 1-0) emission is used to diagnose the presence of large-scale, global velocity fluctuations in molecular clouds. We search for, and find, large-scale flows of atomic material in which the globally turbulent molecular clouds are embedded. This is consistent with the picture of molecular clouds existing as short-lived, turbulent density fluctuations within larger scale atomic flows. Large-scale driving of turbulence in molecular clouds, by converging flows of atomic material, can reconcile recent numerical determinations of the dissipation rate of turbulent energy with the observations, that otherwise, for small-scale driving, leads to unacceptably high cloud luminosities. On the other hand, lack of large-scale shock signatures in the molecular gas, as expected for large-scale driving, may, if not due to an observational bias, require that the large-scale flows are themselves driven by energy injection occurring on smaller scales within molecular clouds.