The Anisotropy in Interstellar Media

星际介质中的各向异性

• 批准号: 203331259
• 负责人: Dr. Hua-bai Li
• 金额: --
• 依托单位: Max-Planck-Institut für Astronomie (MPIA)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/203331259?language=en
• 关键词: Anisotropy; Interstellar; Media

Gravitational contraction, turbulence, and magnetic fields (B-fields) are generally accepted to be the key dynamical processes involved in interstellar media (ISM). How these processes interact with each other to form clouds, cores, and stars is, however, highly controversial. Many parameters that have been defined to describe these processes are isotropic (e.g., turbulent velocity, magnetic pressure, and virial equilibrium), but very recent observations have begun to reveal that density fragmentation and turbulent velocity in ISM may be highly filamentary. At the same time, Galactic B-fields have been found to be strong enough to imprint their orientations in many molecular clouds. These kinds of observations can place crucial constraints on competing ISM scenarios, because not all of them predict the observed anisotropy. Additional observations to increase the sample size are proposed here, along with new experiments designed for the forthcoming instruments and surveys.The challenge of understanding the ISM dynamics owes much to the lack of a practical method for measuring B-field strength. The novel method we proposed recently, based on the difference between ion and neutral turbulence, will be applied to filamentary density structures in molecular clouds. The method can simultaneously measure the energies of turbulence and B-fields, which will greatly help our understanding of the causes of ubiquitous cloud filaments.

引力收缩、湍流和磁场（B场）是星际介质（ISM）的主要动力学过程。然而，这些过程如何相互作用以形成云、核心和恒星是非常有争议的。已经定义来描述这些过程的许多参数是各向同性的（例如，湍流速度、磁压和维里平衡），但最近的观测已经开始揭示，ISM中的密度碎裂和湍流速度可能是高度依赖性的。与此同时，银河系的B场已经被发现足够强大，可以在许多分子云中留下它们的方向。这些类型的观测可以对竞争ISM场景施加关键约束，因为并非所有这些都预测了观测到的各向异性。额外的意见，以增加样本量的建议，这里，沿着与新的实验设计的仪器和surveys.The挑战的理解ISM动力学很大程度上是由于缺乏一个实用的方法来测量B-场强。我们最近提出的新方法，基于离子和中性湍流之间的差异，将被应用于分子云的非定常密度结构。该方法可以同时测量湍流和B场的能量，这将大大有助于我们理解无处不在的云丝的原因。