The Chemistry of the Galactic Halo

ast -0607708机构：德克萨斯大学奥斯汀分校pi: Christopher SnedenTITLE：银河晕的化学。德克萨斯大学奥斯汀分校的Christopher Sneden将承担一个项目，其基本目标是为银河系化学演化理论家提供重要类别的银河系晕星的详细和精确的化学成分。目标将在两个一般项目中解决：1)在相对较小的恒星样本中精确测定几种关键重元素的丰度，这些元素是通过与超新星爆炸有关的事件中目标种子核捕获的短时间快速中子爆发产生的；2)对金属丰度最低的晕星，以及有证据表明其双星伴星过去有过质量传递的恒星进行大样本丰度调查。此外，斯尼登博士和合作者将扩大一个正在进行的项目，结合实验室和太阳/恒星丰度调查选定元素的天文可观测特征。将特别注意那些对早期银河系化学成分调查研究最感兴趣的中性和电离物质。这项工作的更广泛影响包括计算机代码和原子/分子线数据的持续发展、改进和网络传播，以供全球恒星光谱学家社区使用。此外，研究和课程开发与公众宣传之间的联系将会产生，斯尼登博士将积极参与正在进行的一系列针对中学教育工作者的研讨会。

AST-0607708INSTITUTION: University of Texas at AustinPI: Christopher SnedenTITLE: The Chemistry of the Galactic HaloABSTRACTDr. Christopher Sneden, at the University of Texas at Austin, will undertake a program that has as its basic goal providing Galactic chemical evolution theorists with detailed and accurate chemical compositions of important classes of Galactic halo stars. The goal will be addressed in two general projects: 1) Precise abundance determinations in relatively small stellar samples of several key very heavy elements that are manufactured via short-lived, rapid bursts of neutrons captured by target seed nuclei in event(s) associated with supernova explosions; and 2) Large-sample abundance surveys of lowest-metallicity halo stars, and of stars that show evidence for past mass-transfer episodes from their binary companions. Additionally, the Dr. Sneden and collaborators will expand an ongoing program combining laboratory and solar/stellar abundance investigation of astronomically observable features of selected elements. Special attention will be paid to those neutral and ionized species of greatest interest to research on early Galactic chemical composition surveys.Broader impacts of the work include the continued development, refinement, and web-dissemination of computer codes and atomic/molecular line data to the worldwide community of stellar spectroscopists. Additionally, connections between research and course development and public outreach will result, and Dr. Sneden will be an active participant in an ongoing series of seminars to secondary school educators.