Towards Understanding Interstellar Turbulence

理解星际湍流

• 批准号: 0808118
• 负责人: Alexandre Lazarian
• 金额: $ 28.04万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0808118&HistoricalAwards=false
• 关键词: Towards; Understanding; Interstellar; Turbulence

Although turbulence is chaotic, it can be described and understood. Turbulence is governed by well-defined statistical laws that can be studied and then successfully applied to solving astrophysical problems. In this project, Dr. Alexandre Lazarian (University of Wisconsin - Madison) seeks to advance theoretical understanding of magnetized turbulence in the interstellar medium (ISM) by both studying these laws and comparing theory with observations. These studies will build upon the existing research base and the enabling achievements obtained through Dr. Lazarian's earlier work that focused on the spectra of turbulence and its implications for cosmic rays. The present project is to address the role of small regions within the ISM turbulence in which the physical conditions are far from the average (called "intermittency"), as well as the feedback of cosmic rays to the compressible turbulence. In addition, this research will continue developing, testing, and applying new tools for extracting turbulence spectra from observations of the velocity profiles of spectral lines. As the result of this research, the observational community will have new tools to study turbulence and its anisotropy, as well as the topology of the ISM. The appearance, evolution, and overall properties of a spiral galaxy are strongly influenced by its ISM. In turn, the nature of the ISM and many processes taking place within it (such as star-formation) are determined by the magnetic turbulence that stirs it. Examining magnetic turbulence at a fundamental level is vital to understanding many processes. Turbulence cannot be confidently understood using "brute force" numerical approaches only; the fluid motions simulated by computers differ from astrophysical ones by a huge difference in Reynolds numbers. In addition to the research that will be carried out under this project, Dr. Lazarian will mentor a graduate student as well as supervise REU and undergraduate student research projects. Dr. Lazarian will also carry out outreach activities, such as public lectures, and will make the statistical tools developed as a part of this project publicly available.

尽管湍流是混乱的，但可以描述和理解。 湍流受到定义明确的统计定律的控制，可以研究，然后成功地应用于解决天体物理问题。 在这个项目中，威斯康星大学 - 麦迪逊大学亚历山大·拉扎里安（Alexandre Lazarian）博士试图通过研究这些法律和比较理论与观察的比较，以提高对星际培养基（ISM）中磁化湍流的理论理解。这些研究将基于现有的研究基础以及通过Lazarian博士的早期工作所获得的促进成就，该研究的重点是湍流及其对宇宙射线的影响。目前的项目是针对ISM湍流中小区域的作用，在ISM湍流中，物理条件远非平均值（称为“间歇性”），以及宇宙射线对可压缩湍流的反馈。此外，这项研究将继续开发，测试并应用新工具来从观察光谱线的速度曲线中提取湍流光谱。 作为这项研究的结果，观察社区将拥有研究湍流及其各向异性的新工具，以及ISM的拓扑。螺旋星系的外观，进化和整体特性受其ISM的强烈影响。反过来，ISM的性质和其中发生的许多过程（例如恒星形成）是由搅动它的磁性湍流确定的。在基本水平上检查磁性湍流对于理解许多过程至关重要。 只能使用“蛮力”数值方法对湍流无法自信地理解；计算机模拟的流体运动与天体物理学的动作不同，雷诺数的差异很大。 除了将在该项目下进行的研究外，Lazarian博士还将指导研究生，并监督REU和本科生研究项目。 Lazarian博士还将开展外展活动，例如公开演讲，并将公开开发统计工具作为该项目的一部分。