Metal-Containing Molecules as Probes of Interstellar/Circumstellar Gas: From Chemistry to Nucleosynthesis

含金属分子作为星际/星际气体探针：从化学到核合成

• 批准号: 0204913
• 负责人: Lucy Ziurys
• 金额: $ 26.25万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0204913&HistoricalAwards=false
• 关键词: Metal; Containing; Molecules; Probes; Interstellar

AST-0204913PI ZiurysDuring the past thirty years since the initial discovery of interstellar molecules at radio wavelengths, much has been learned about the chemistry of such species, and their subsequent use as tracers of the physical conditions in dense gas has proved extremely valuable. Despite the obvious success of molecular astrophysics, there are still many unanswered questions pertaining to interstellar molecules, one of which concerns the chemistry and abundances of species containing the metallic elements. This project will continue the investigation of the chemistry of the metallic elements in the interstellar medium through a joint laboratory/observational/chemical modeling program. The observations will identify the major molecular carriers of the metallic elements incircumstellar envelopes of evolved stars and in dense clouds through measurements in the millimeter/sub-mm wavelength region. This data will lead to the establishment of likely synthetic pathways, be it gas-phase radiative association reactions, dust-grain processes or formation in shock waves. The laboratory work will supply the necessary millimeter and sub-mm rotational spectra from which rest frequencies for the astronomical searches are obtained. Finally, chemical modeling of metal chemistry in circumstellar envelopes will be performed in conjunction with new nucleosynthesis calculations. A complete picture will thus be constructed of metal-containing molecules, their abundances, formation mechanisms, and significance for understanding mass loss of the heavier elements from circumstellar envelopes to the interstellar medium.***

AST-0204913 PI Ziurys在过去的三十年里，自从在无线电波长上首次发现星际分子以来，人们对这类物质的化学性质有了很大的了解，后来将它们用作稠密气体中物理条件的示踪剂，证明是非常有价值的。尽管分子天体物理学取得了明显的成功，但仍然有许多关于星际分子的问题没有得到解答，其中之一是关于含有金属元素的物质的化学和丰度。该项目将通过一个联合实验室/观测/化学模拟方案，继续研究星际介质中金属元素的化学性质。这些观测将通过毫米/亚毫米波长区域的测量，确定演化恒星的星周包层和致密云中金属元素的主要分子载体。这些数据将导致建立可能的合成途径，无论是气相辐射缔合反应、尘埃颗粒过程还是冲击波的形成。实验室工作将提供必要的毫米和亚毫米旋转光谱，从中获得天文搜索的静止频率。 最后，将结合新的核合成计算进行环星包层中金属化学的化学建模。因此，一个完整的图片将构建含金属的分子，它们的丰度，形成机制，以及理解从星周包层到星际介质的重元素的质量损失的意义。