Galactic archaeology — fossil evidence of how our Galaxy's disk formed

我们银河系中巨大的恒星成分包含着它是如何形成的化石印记。目前的星系形成模型，冷暗物质（CDM）范式，认为它们是在数十亿年的时间里由较小的系统合并而成的，但宇宙学模拟无法重现单个星系的关键特性。预测的高水平的合并活动使得形成像我们这样的星系非常困难。这是目前取得进展的主要障碍。该项目旨在通过观测来评估合并在星系形成过程中的重要性，这是CDM的关键测试。该项目将用HERMES宽视场光谱仪瞄准银河系盘和凸起中的恒星。

The vast stellar content of our Galaxy contains the fossil imprints of how it was formed. The current model for galaxy formation, the Cold Dark Matter (CDM) paradigm, is that they have built up over billions of years by the merging of smaller systems, but cosmological simulations fail to reproduce the key properties of individual galaxies. The predicted high level of merger activity makes it very difficult to form galaxies like our own. This is the key stumbling block to progress at the present time. The project aims to assess observationally how important mergers have been in the formation of the Galaxy, the critical test of CDM. The project will target the stars in the Galactic disk and bulge with the HERMES wide-field spectrograph.