High Resolution Spectroscopy of the Galactic Halo

96-18364 Sneden，Christopher Sneden博士将通过获得银河系晕中关键恒星群的高分辨率光谱学，对恒星核合成和银河系早期化学演化的基本问题进行多样化的研究。 星系晕天体具有丰富多样的化学成分，为早期化学和动力学演化提供了基本线索。 最缺金属的恒星中超重元素丰度的特征揭示了第一代银河系超新星的性质;球状星团中轻元素的丰度表明了恒星内部复杂的氢核合成和内部混合;星系晕中恒星视线上的星际吸收特征描绘了银河系晕中的大型星际云。 Sneden博士最有趣的工作之一将是对钍元素的研究，它有可能提供银河系年龄的估计。 ***

96-18364 Sneden, Christopher Dr. Sneden will carry out a diverse program of research into fundamental issues of stellar nucleosynthesis and the early chemical evolution of the Milky Way Galaxy by obtaining highresolution spectroscopy of key stellar populations in the Galaxy's halo. Galactic halo objects possess richly varied chemical compositions, which provide fundamental clues to early chemical and dynamical evolution. The signature of abundances of very heavy elements in the most metaldeficient stars reveal the nature of the first generation of Galactic supernovae; the abundance of light elements in globular cluster stars indicate complex hydrogen nucleosynthesis and internal mixing in stellar interiors;the interstellar absorption features on lines of sight toward stars in the halo map out large interstellar clouds in the Galactic halo. Among the most interesting of Dr. Sneden's work will be studies of the element Thorium, which holds the potential to provide an estimate of the age of the Galaxy. ***