标题： 分子云中结构的形成：案例研究 显示英文标题

标题： Formation of Structure in Molecular Clouds: A Case Study

摘要： 分子云（MCs）具有高度的结构和“湍流”。 碰撞的中性氢气流被认为可能是分子云的可能来源，由于动力学和热不稳定性，从而留下了丝状结构。 我们提出了一个二维数值分析，研究通过汇聚的HI流形成分子云。 即使流速适中且完全均匀的流入，也会出现非线性密度扰动，这些扰动可能是分子云的前体。 因此，我们认为分子云不可避免地形成具有显著结构，例如强密度和速度波动，这些为后续在各种星系和星系外环境中的引力坍缩和恒星形成提供了初始条件。 显示英文摘要

摘要： Molecular clouds (MCs) are highly structured and ``turbulent''. Colliding gas streams of atomic hydrogen have been suggested as a possible source of MCs, imprinting the filamentary structure as a consequence of dynamical and thermal instabilities. We present a 2D numerical analysis of MC formation via converging HI flows. Even with modest flow speeds and completely uniform inflows, non-linear density perturbations as possible precursors of MCs arise. Thus, we suggest that MCs are inevitably formed with substantial structure, e.g., strong density and velocity fluctuations, which provide the initial conditions for subsequent gravitational collapse and star formation in a variety of galactic and extragalactic environments.