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.

赫布斯特博士和他的团队继续在星际介质的不同环境中进行天体化学研究，从分子云中的化学到AGB恒星的恒星流出，再到益生菌分子的形成，以及某些类型的河外来源。重点是改进区域的化学模拟，ALMA和其他干涉仪将详细观察这些区域，以研究源的动力学和异质性。这项工作是通过化学网络计算完成的，其中包括气相反应和气-表面(冰)反应，以及动力学考虑。对星际介质分子光谱的观察可以分析，以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摧毁的，PI和他的团队创建了包括气相和颗粒表面过程的大型化学反应网络。结合均匀或非均相源的物理模型，这些化学网络计算被用于计算气体中和尘埃颗粒表面的分子丰度。然后，通过与观测数据的比较，我们可以获得有关来源的身体状况和寿命的信息。博士后和研究生培训是该项目的重要组成部分。PI在天体化学方面的工作对分子在我们的银河系和其他星系中用作星际介质探测器的蓬勃发展起到了重要作用。现在，有关星际云扩散和致密的大部分知识都来自于对这些区域中的分子告诉我们什么的理解。分子天文学领域已经成为一项世界性的努力，观测天文学家、理论化学家、实验科学家和建模人员在共同感兴趣的问题上进行合作。