Quantitative insight into interstellar turbulence

对星际湍流的定量洞察

• 批准号: 1212096
• 负责人: Alexandre Lazarian
• 金额: $ 29.99万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1212096&HistoricalAwards=false
• 关键词: Quantitative; insight; into; interstellar; turbulence

This is a continuation of Dr. Lazarian's theoretical work on the influence of magnetic field diffusion in turbulent star-forming clouds on the star formation process. The appearance, evolution, and overall properties of a spiral galaxy are strongly influenced by its interstellar medium (ISM). In turn, the nature of the ISM and many processes within it, such as star formation, are determined by the magnetic turbulence that stirs the ISM. Properties of turbulent fluids cannot be confidently understood using only numerical approaches; and the fluid motions simulated by computers differ from astrophysical ones by a huge difference in Reynolds numbers.The present work focuses on the role that magnetic reconnection plays in star formation, and investigates the sources and effects of turbulence in different phases of the ISM. Although turbulence is chaotic, it can be described and understood by applying well defined statistical laws to solve astrophysical problems.The work improves the comparison of theory with observations. The studies employ well-tested numerical codes already in place. The principal investigator and his team will continue to develop, test, and apply new tools for extracting properties of turbulence (such as turbulence spectra and sonic Mach number of turbulence) from observations.The statistical tools from this study are made publicly available and provide new tools to the observational community to study turbulence, its driving, and its magnetization. A graduate student will work on this project. This project also offers Research Experience for Undergraduate (REU) students.

这是拉扎里安博士关于湍流恒星形成云中磁场扩散对恒星形成过程影响的理论工作的延续。螺旋星系的外观、演化和整体特性很大程度上受到其星际介质（ISM）的影响。反过来，ISM 的性质以及其中的许多过程（例如恒星形成）是由搅动 ISM 的磁湍流决定的。仅使用数值方法无法自信地理解湍流流体的特性；计算机模拟的流体运动与天体物理运动的不同之处在于雷诺数存在巨大差异。目前的工作重点是磁重联在恒星形成中的作用，并研究了ISM不同阶段湍流的来源和影响。尽管湍流是混沌的，但可以通过应用明确的统计定律来描述和理解它来解决天体物理问题。这项工作改进了理论与观测的比较。这些研究采用了已经经过充分测试的数字代码。首席研究员和他的团队将继续开发、测试和应用新工具，从观测中提取湍流特性（例如湍流谱和湍流的声速马赫数）。这项研究的统计工具是公开的，为观测界提供新工具来研究湍流、其驱动和磁化。一名研究生将从事该项目。该项目还为本科生（REU）提供研究经验。