Collaborative Research: Simulating Two-Fluid MHD Turbulence in Star Forming Molecular Clouds on the Blue Waters System

合作研究：模拟 Blue Waters 系统上恒星形成分子云中的两流体 MHD 湍流

• 批准号: 1713782
• 负责人: Alexandre Lazarian
• 金额: $ 2万
• 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: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1713782&HistoricalAwards=false
• 关键词: Collaborative; Research; Simulating; Two; Fluid

Astrophysics is at the threshold of a new data-rich and simulation-rich era in star-formation studies. The question of how stars form is fascinating in itself and has a great impact on several other areas of astrophysics. There is a general consensus that a predominant amount of star formation in our Galaxy takes place in molecular clouds, and specifically in giant molecular clouds (GMC). Consequently, NASA has made multi-million dollar investments in instruments such as HAWC+ on the SOFIA airborne observatory with the specific goal of understanding the turbulent nature of star forming clouds. This project on Blue Waters will use the petascale capabilities of the system to validate theories of star formation by simulating the same processes the NASA's instruments are currently measuring.This project will carry out simulations on Blue Waters that integrate the ions and the neutrals to reproduce the turbulent, partially ionized gas in which stars form. Since neutral gas does not couple to the magnetic field, but ionized gas do, the project has built frontline simulation capabilities for simulating two-fluid plasmas. Simultaneously, the project has built theoretical and numerical analysis tools that will enable cross-comparison of simulations with observations. This cross-comparison provides important verification of theories of star formation. Further diagnostics that emerge from the simulations will also be used to motivate more detailed observations. In this fashion, Blue Waters will enable theory, computation and detailed observations to support one another. In addition, the project intends to combine education in computational astrophysics with code releases of their simulation tools to the greater astrophysics community.

天体物理学处于恒星形成研究中新的数据丰富和模拟时代的阈值。恒星形成如何引人入胜的问题本身对天体物理学的其他几个领域产生了很大的影响。人们普遍的共识是，我们星系中主要的恒星形成发生在分子云中，特别是在巨型分子云（GMC）中。因此，NASA已在索非亚空降天文台上对HAWC+等工具进行了数百万美元的投资，其特定目标是了解恒星形成云的动荡性。该项目在蓝色水域上的项目将使用系统的Petascale功能来验证恒星形成理论，通过模拟NASA的仪器目前正在测量的相同过程。该项目将在蓝色水域上进行模拟，以整合离子和中性物质，以重现湍流的，部分湍流的，部分电离的气体，以哪些形式产生恒星。 由于中性气体没有将磁场与电离气体搭配在一起，但该项目已建立了前线模拟功能，以模拟两流体的等离子体。同时，该项目构建了理论和数值分析工具，该工具将使模拟与观测值进行交叉比较。这种交叉比较提供了对恒星形成理论的重要验证。从模拟中出现的进一步诊断也将用于激发更详细的观察结果。以这种方式，蓝色水域将使理论，计算和详细的观察值相互支持。 此外，该项目旨在将计算天体物理学中的教育与更大的天体物理学社区的模拟工具的代码发布相结合。

项目成果

Distribution of Velocity Gradient Orientations: Mapping Magnetization with the Velocity Gradient Technique

• DOI: 10.3847/1538-4357/aad7ff
• 发表时间: 2018-02
• 期刊: The Astrophysical Journal
• 作者: A. Lazarian;K. Yuen;K. Ho;Jun-De Chen;Victor Lazarian;Zekun Lu;Zekun Lu;Bo Yang;Yue Hu;Yue Hu

Mapping of the Structure of the Galactic Magnetic Field with Velocity Gradients: Test Using Star Light Polarization

• DOI: 10.3847/1538-4357/ab0552
• 发表时间: 2018-05
• 期刊: The Astrophysical Journal
• 作者: Diego F. González-Casanova;A. Lazarian