U.S.-Australia Cooperative Science Program: Discovery and Analysis of Extremely Low Metallicity Stars in the Galactic Halo

9417547 Beers这个奖项将部分资助Timothy Beers博士和他的一名来自密歇根州立大学物理与天文学系的研究生在三年的时间里的旅费，使他们能够每人访问一次，与来自芒特斯特罗姆洛和西丁泉天文台的John E.Norris博士和来自澳大利亚埃平的英澳天文台的Sean Ryan博士进行合作研究。合作研究的重点将是发现和分析银晕中极低的金属丰度。大量极度缺乏金属的恒星提供了有关宇宙学问题、银河系的形成和演化以及恒星中轻元素的产生和加工的关键信息。通过这一合作对南半球天空中的低金属丰度候选天体进行观测，将大大增加金属丰度低于太阳值的千分之一的恒星的数量，从而能够对我们银河系和宇宙的形成和演化进行广泛的研究。具体的研究包括：将极度贫金属星的金属丰度分布函数与银河系富集物模型的预测进行详细比较，研究贫金属星的运动学随丰度和与银河面的距离的变化，以及对恒星中轻元素和重元素相对丰度的高分辨率观测，这反过来又对恒星演化和早期宇宙的核合成过程施加基本限制。除了这个奖项将为有共同兴趣的澳大利亚天文学家提供机会外，该项目还将带来更多的观看机会，使用澳大利亚的设施来测量南半球的天空。

9417547 Beers This award will partially support the travel expenses, over a three year period, for Dr. Timothy Beers and one of his graduate students from the Department of Physics and Astronomy at Michigan State University, to enable them to each made one visit to conduct cooperative research with Dr. John E. Norris of the Mount Stromlo and Siding Spring Observatories and Dr. Sean Ryan of the Anglo-Australian Observatory in Epping, Australia. The collaborative research will focus on the discovery and analysis of extremely low metallicity in the Galactic Halo. Large numbers of extremely metal-deficient stars provide crucial information on questions in cosmology, the formation and evolution of the Galaxy, and the production and processing of light elements in stars. Observations of low-metallicity candidates through the southern hemisphere sky, made possible through this collaboration, will provide a significant increase in the numbers of stars with metal abundances less than 1/1000th of the solar value, thereby enabling a wide range of investigations concerning the formation and evolution of our Galaxy, and the Universe. Specific investigations include a detailed comparison of the metallicity distribution function of extremely metal-poor stars with predictions of Galactic enrichment models, a study of the kinematics of metal-deficient stars as a function of abundance and distance from the Galactic plane, and high-resolution observations of the relative abundances of the light and heavy elements in stars, which in turn place fundamental constraints on stellar evolution and on nucleosynthesis processes in the early Universe. In addition to the access this award will provide to the Australian astronomers with mutual interests, the project will result in additional viewing opportunities using Australian facilities to survey the southern hemisphere sky.