Chemistry and kinematics of stars in dwarf galaxies

矮小星系是否与星系形成模型中描述的合并形成大星系的原星系碎片相同？银河系厚盘是在中间纪元通过盘加热合并形成的吗？矮球星系的恒星形成历史与富含气体的矮小不规则系统有多相似？这些问题现在可以通过对局部群中低质量矮星系中的单个恒星进行详细的化学分析来解决。有了8到10米的大型望远镜和高效率的光谱仪。我的研究涉及测定矮球星系中的老星和不规则星系中的年轻恒星的化学成分。目前，将矮星系中的恒星与我们银河系中的类似恒星进行比较，显示出很少的共同点，但随着多目标光谱仪的结果开始出现，我们即将取得突破。对每个矮星系数百颗恒星的分析使我们能够检查分级星系的形成。以及测试我们对恒星核合成的假设。下一代望远镜和仪器将使人们有可能首次接触到更孤立的矮星系中的老恒星，这可能不同于我们目前能够研究的附近系统，以及更远的矮星系中的恒星，比如围绕仙女座星系运行的恒星，可能还包括室女座星系团中的恒星。

Are dwarf galaxies the same as the protogalactic fragments that merged to form large galaxies, as described in the hierarchical galaxy formation models?    Was the Galactic thick disk formed through disk heating by a merger at an intermediate epoch?  How similar are the star formation histories of the dwarf spheroidal galaxies to the gas rich dwarf irregular systems?    Questions such as these can now be addressed through detailed chemical analyses of the individual stars in the low-mass dwarf galaxies in the Local Group, made possible with the large 8 to 10-m class telescopes and high efficiency spectrographs.  My research involves the determination of the chemical composition of old stars in dwarf spheroidal galaxies and young stars in dwarf irregular galaxies.   Currently, comparisons of stars in dwarf galaxies with similar stars in our  Galaxy show very little in common, but we are on the verge of a breakthrough as results from the multi-object spectrographs begin to emerge.   Analyses of hundreds of stars per dwarf galaxy allow us to examine hierarchical galaxy formation, as well as test our assumptions about stellar nucleosynthesis in general.  The next generation of telescopes and instrumentation will make it possible to reach the old stars in the more isolated dwarf galaxies for the first time, which may be different from the nearby systems that we are currently able to study, as well as stars in more distant dwarf galaxies such as those orbiting the Andromeda galaxy and possibly those in the Virgo cluster.