Numerical Simulations of Non-Equilibrium Plasmas and Their Spectra

非平衡等离子体及其光谱的数值模拟

• 批准号: 0307720
• 负责人: Gary Ferland
• 金额: $ 36.02万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307720&HistoricalAwards=false
• 关键词: Numerical; Simulations; Non; Equilibrium; Plasmas

AST-0307720FerlandMuch of our understanding of the chemical evolution of the cosmos comes from the analysis of emission or absorption lines produced in interstellar gas. This project is a simultaneous attack on several broad fronts extending from nearby HII regions to luminous quasars with the common theme of developing the tools needed to chart their chemical evolution. Much of this work centers on the development and application of the large-scale plasma simulation code Cloudy. This is a multi-pronged effort that combines observational astrophysics, numerical simulations, and atomic and molecular physics. These steps are strongly interwoven and progress from the Orion Nebula, to the giant extragalactic H II region 30 Doradus, and eventually to the intervening systems seen by their absorption lines in spectra of distant quasars. Starting with a complete model of the neutral hydrogen molecule, with a fully self-consistent spectral simulation, the project will then extend to helium-like species, with an important first application to the primordial helium abundance. With other extensions, the result should be a fully self-consistent description of how gas flows from its fully molecular state, eventually into regions where ions are formed by photo-ionization, resulting in an almost parameter-free description of the entire environment. The models will be tested against very deep optical spectroscopy of the Orion Nebula and of 30 Doradus, the nearest giant extragalactic HII region.The spectral simulation code at the heart of this project is used by other researchers in work that produces over a hundred papers a year. Code development, with strong involvement by students, including as parts of their doctoral theses, therefore has a very wide impact on the community. Results from this project will also be used by the researcher to assist with a scheme under development which will bring in-service teachers from central Kentucky to his University campus for research briefings and teaching strategy discussions.

AST-0307720 FERLANDMUCH我们对宇宙化学演化的理解来自对星际气体中产生的排放或吸收系线的分析。该项目是对从附近的HII区域延伸到发光的类星体的几个广泛阵线的同时攻击，其共同主题是开发制定其化学演化所需的工具。这项工作的大部分集中在大规模等离子体模拟代码的开发和应用上。这是一项多管齐下的努力，结合了观察性天体物理学，数值模拟以及原子和分子物理学。这些步骤是牢固地交织在一起的，并从猎户座星云，到巨大的乳乳外H II区域30多拉德斯，最终转变为远处类星体光谱中其吸收系线所看到的中间系统。从具有完全自洽的光谱模拟的中性氢分子的完整模型开始，该项目将延伸至类似氦的物种，并在原始氦的丰度中进行了重要的首次应用。 随着其他扩展，结果应该是对气体从其完全分子状态流动方式流动的完全自洽的描述，最终进入了通过光学化形成离子的区域，从而对整个环境产生了几乎无参数的描述。 这些模型将针对猎户座星云的非常深的光谱和30个Doradus（最近的巨大巨型外层次HII区域）进行测试。该项目核心的光谱模拟代码在工作中使用的其他研究人员使用，该研究人员在工作中生产一百多篇论文。 代码开发，学生的参与很大，包括作为博士论文的一部分，因此对社区产生了很大的影响。 研究人员还将利用该项目的结果来协助制定计划，该计划将将肯塔基州中部的在职教师带到他的大学校园进行研究简介和教学策略讨论。