Probing Element Abundance Changes in Galactic Stars

我们银河系中恒星的组成对它的诞生和恒星形成的历史有着至关重要的线索。恒星在它们的内部制造元素。恒星死亡时，会将新元素返回到银河系的气体中。研究人员试图利用恒星的光谱丰度来理解元素的积累是如何导致今天的复杂元素周期表的。调查人员有三个目标。他们的首要目标是提高化学成分分析的质量。他们将获得用于光谱分析的基本实验室数据。其次，它们将显著增加重要恒星群中被研究的恒星的数量。通过这项研究，他们将研究各种银河系恒星群的成员。第三，他们将为研究和教育界提供服务。他们将向所有人免费提供新的实验室数据和丰富的分析软件。他们还将与德克萨斯州的一群科学教育工作者合作，将天文研究与他们的教学工作联系起来。研究人员将提供对我们银河系光晕中许多贫金属星中铁族元素丰度的非常准确的测量。他们将在银盘的大约20个疏散星系团的大样本中获得丰富的碳、氮、氧和锂，以及碳同位素比率。这项工作将独特地利用新获得的高分辨率光谱，覆盖光学和红外光谱域的广泛区域。他们将通过将光谱与Gaia天体测量卫星提供的运动学相匹配来搜索银河系中的恒星流。他们还将利用星系团和银盘总场中温暖红巨星的新红外光谱来探索这一问题。调查人员将继续发布实验室原子和分子光谱线数据的重大更新，并改进我们公开可用的光谱分析代码。调查人员将继续他们长期努力，以提高德克萨斯州的科学教育质量。他们将与一群积极进取的中学科学教育工作者合作。他们讲授最新的天文研究，并让教师参与可以带回教室使用的项目。他们还将为教师提供参与望远镜使用的机会，在麦克唐纳天文台举办研讨会，并参加美国天文学会的会议。

The compositions of stars in our Milky Way Galaxy hold vital clues to its birth and history of forming stars. Stars make elements in their interiors. At their deaths, stars return the new elements into the gas of the Galaxy. The investigators seek to use abundances of stars, derived from their spectra, to understand how the buildup of elements led to the complex Periodic Table of today. The investigators have three goals. Their first goal is improving the quality of chemical composition analyses. They will obtain basic laboratory data that go into the spectrum analyses. Second, they will significantly augment the number of stars studied in important groups of stars. Through this they will study members of various Galactic star populations. Thirdly, they will provide service to the research and educational communities. They will make the new lab data, and abundance analysis software freely available to all. They will also work with a group of Texas science educators to link astronomical research with their teaching efforts.The investigators will provide very accurate measurements of iron-group element abundances in many metal-poor stars of the halo of our Galaxy. They will derive abundances of carbon, nitrogen, oxygen, and lithium, as well as carbon isotopic ratios in large samples of about 20 open clusters of the Galactic disk. This work will uniquely take advantage of newly-acquired high resolution spectra covering broad regions of both optical and infrared spectral domains. They will search for star streams in the Galaxy by mating optical spectra with kinematics to be provided by the Gaia astrometric satellite. They will also explore this issue with new infrared spectra of warm red giant stars in clusters and in the general field of the Galactic disk. The investigators will continue to release major updates of lab atomic and molecular spectral line data, and to improve our publicly-available spectrum analysis codes.The investigators will continue their long-standing effort to improve the quality of science education in the state of Texas. They will work with a highly-motivated group of secondary science educators. They give talks on the latest astronomical research, and to engage teachers in projects that can be carried back to use in their classrooms. They will also provide opportunities for teachers to participate in telescope usage, to have workshops at McDonald Observatory, and to attend meetings of the American Astronomical Society.