Observational study of origin of the interstellar turbulence

我们通过高分辨率12CO观测发现了分子云的小尺度结构。与在分子云中间观察到的典型结构相比，小尺度结构的光谱速度色散要小得多。这表明分子云不是均匀的实体，而是由热平衡状态下的冷致密小尺度结构组成的，正如理论两相介质模型和热中性介质的热不稳定性所表明的那样。这些结果为分子云的形成提供了线索，这是星际物理学中最大的问题之一。为了解决这一问题，计划利用ALMA等后续的高角分辨率分子和原子气体观测。

We discovered small-scale structures of molecular clouds by high-resolution 12CO observations. The small-scale structures have much smaller velocity dispersions of the spectra compared to typical ones observed in the middle of molecular clouds. These imply that molecular clouds are not uniform entities, but consist of cold and dense small-scale structures in the thermal equilibrium, as suggested by the theoretical two-phase medium model and thermal instability of the warm neutral medium. These results gave clues about molecular cloud formation, one of the biggest issues of the interstellar physics. The follow-up observations of molecular and atomic gas with high angular resolution by ALMA and others are scheduled to solve the problems.