New Chemical Simulations for the Age of ALMA

赫布斯特博士和他的团队继续在星际介质的不同环境中研究天体化学，从分子云的化学到AGB恒星的恒星流出，再到生命前分子的形成，以及一些类型的河外来源。重点是改进区域的化学模拟，这些区域将被ALMA和其他干涉仪详细观测，以研究源的动力学和非均质性。这项工作是通过化学网络计算完成的，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和他的团队创建了大型的化学反应网络，其中包括气相和颗粒表面过程。结合源的物理模型，无论是均匀的还是非均匀的，这些化学网络计算被用来计算气体和尘埃颗粒表面的分子丰度。通过与观测数据的比较，我们可以得到有关物质条件和源寿命的信息。博士后和研究生的培养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系星际介质探测器的蓬勃发展中发挥了重要作用。现在，关于弥散和稠密星际云的大部分知识都来自于对这些区域分子所告诉我们的信息的理解。分子天文学已经成为一个世界性的领域，在这个领域里，观测天文学家、理论化学家、实验科学家和建模者就共同感兴趣的问题进行合作。

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.