Formation histories of galactic halos via chemical abundance analyses of near-by stellar systems

我建议成立一个研究小组来研究邻近星系的形成，特别关注我们银河系及其最近的邻居M31星系的光晕。目的是利用ESO/VLT、LBT、麦哲伦和凯克望远镜上的仪器以及其他现有和档案数据获得的高分辨率光谱，测量附近矮星系和球状星团中恒星的化学元素丰度。这些数据将使用最先进的技术进行分析。通过比较最低质量矮星系与银河系外围星团和星系晕恒星的性质，可以估计出这些系统在多大程度上可以被认为是我们银河系的组成部分。此外，人们认为矮星系是宇宙中最早恒星形成的地方，可以通过它们的金属贫乏恒星的化学特征来标记。最后，对M31光晕的窄带光度测定将使人们能够识别出这个星系外部区域和亚结构中的主要恒星群。由此可以有效地重建M31的形成历史。

I propose to establish a research group to investigate the formation of nearby galaxies, with a particular focus on the halos of our Milky Way galaxy and its nearest neighbour, the M31 galaxy. The aim is to measure chemical element abundances of stars in near-by dwarf galaxies and in globular clusters using high-resolution spectroscopy obtained with instruments at the ESO/VLT, LBT, Magellan, and Keck telescopes, and additional existing and archival data. These data will be analyzed using state-of-the-art techniques. By comparing the properties of the lowest-mass dwarf galaxies with star clusters in the outskirts of the Milky Way and with stars of the Galactic halo, it can be estimated to what extent such systems can be considered as building blocks of our Milky Way. Furthermore, it is believed that the dwarf galaxies are the sites of the earliest star formation in the Universe, which can be tagged via the chemical characteristics of their metal poor stars. Finally, narrowband photometry in the M31 halo will allow one to identify the predominant stellar populations in the outer regions and in substructures of this galaxy. From this, M31’s formation history can be efficiently reconstructed.