论文标题
从弥漫性气体到致密的分子云芯
From diffuse gas to dense molecular cloud cores
论文作者
论文摘要
分子云是星系的基本要素：它们是将弥漫性气体转化为恒星的通道。尚未完全理解他们如何做的详细过程。我们从量表$ \ sim〜$ 1〜kpc降到细丝和核心尺度的当前对分子云及其子结构的知识。我们首先回顾了从温暖的弥散性星际培养基到寒冷和致密的分子云，分子形成的过程以及热和重力不稳定性的作用的云形成机制。我们还讨论了云收集其质量的主要物理机制，并注意到所有这些都可能在过程的各个阶段中发挥作用。为了理解云的动力学，我们然后对广泛使用的病毒定理进行了批判性综述，及其与分子云的可测量特性的关系。由于这些属性是我们了解云的动态状态的工具，因此我们对它们进行了严格的分析。我们最终讨论了分子云的无处不在丝状结构及其与Prestellar核心和恒星形成的联系。
Molecular clouds are a fundamental ingredient of galaxies: they are the channels that transform the diffuse gas into stars. The detailed process of how they do it is not completely understood. We review the current knowledge of molecular clouds and their substructure from scales $\sim~$1~kpc down to the filament and core scale. We first review the mechanisms of cloud formation from the warm diffuse interstellar medium down to the cold and dense molecular clouds, the process of molecule formation and the role of the thermal and gravitational instabilities. We also discuss the main physical mechanisms through which clouds gather their mass, and note that all of them may have a role at various stages of the process. In order to understand the dynamics of clouds we then give a critical review of the widely used virial theorem, and its relation to the measurable properties of molecular clouds. Since these properties are the tools we have for understanding the dynamical state of clouds, we critically analyse them. We finally discuss the ubiquitous filamentary structure of molecular clouds and its connection to prestellar cores and star formation.
