New Chemical Simulations for the Age of ALMA

ALMA 时代的新化学模拟

• 批准号: 1105111
• 负责人: Eric Herbst
• 金额: $ 50.27万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1105111&HistoricalAwards=false
• 关键词: New; Chemical; Simulations; Age; ALMA

Dr. Herbst and his team continue their investigations of astrochemistry in different environments of the interstellar medium, ranging from chemistry in molecular clouds to stellar outflows from AGB stars to the formation of prebiotic molecules, and some types of extragalactic sources. The focus is on improved chemical simulations of regions that will be observed in detail by ALMA and other interferometers to study both the dynamics and heterogeneity of sources. The work is done with chemical network computations which include gas-phase reactions and gas-surface (ice) reactions, as well as kinetic considerations. Observations of molecular spectra of the interstellar medium can be analyzed to tell us about the physical conditions of the objects in which the molecules reside. In order to understand how molecules are formed and destroyed, the PI and his team have created large networks for chemical reactions which include both gas-phase and grain-surface processes. Coupled with physical models of sources, either homogeneous or heterogeneous, these chemical network computations are used to calculate molecular abundances both in the gas and on the surfaces of dust grains. A comparison with observational data then gives us information on physical conditions and lifetimes of sources.Postdoc and graduate student training is a vital part of this project. The work in astrochemistry by the PI has been important in the burgeoning use of molecules as probes of the interstellar medium in our galaxy and others. Much of the knowledge of diffuse and dense interstellar clouds now comes from an understanding of what molecules in these regions tell us. The field of molecular astronomy has become a worldwide endeavor in which observational astronomers, theoretical chemists, experimental scientists, and modelers collaborate on problems of mutual interest.

Herbst博士和他的团队继续研究星际介质不同环境中的天体化学，从分子云中的化学到AGB恒星的恒星流出，再到生命前分子的形成，以及某些类型的河外来源。重点是改进对将由阿尔马和其他干涉仪详细观察的区域的化学模拟，以研究源的动力学和异质性。这项工作是与化学网络计算，其中包括气相反应和气体表面（冰）反应，以及动力学的考虑。对星际介质分子光谱的观测可以通过分析来告诉我们分子所在物体的物理条件。为了了解分子是如何形成和破坏的，PI和他的团队已经创建了包括气相和颗粒表面过程的化学反应的大型网络。再加上物理模型的来源，无论是同质或异质，这些化学网络计算被用来计算分子丰度的气体和表面上的尘埃颗粒。通过与观测数据的比较，我们可以了解到放射源的物理条件和寿命。博士后和研究生培训是这个项目的重要组成部分。PI在天体化学方面的工作在分子作为我们银河系和其他星际介质探测器的新兴应用中非常重要。现在，关于弥漫和密集星际云的大部分知识都来自于对这些区域中分子的了解。分子天文学领域已经成为一个全球性的奋进，其中观测天文学家，理论化学家，实验科学家和建模者合作解决共同感兴趣的问题。