太阳邻域化学子结构的探测与起源研究

太阳邻域的运动学子结构在大尺度上主要是由一些弧状和脊状结构组成，弧状结构的周围分布着许多移动星群。 但是这些运动学子结构主要来自于银河系的非轴对称引力势（棒、旋臂），以及巨分子云或者银河系卫星星系的扰动，绝大多数没有呈现一致性的化学性质。 我们计划利用LAMOST光谱提供的视向速度以及多种元素的化学丰度，结合Gaia精确的天测数据（视差、自行）在太阳邻域探测化学性质一致的子结构，它们可能来自于星团的瓦解，也可能是被银河系吸积的矮星系的残骸。我们不但会在运动学空间利用多维小波分析在小尺度上探测化学一致性的子结构，也在化学空间直接探测子结构。并对这些化学一致性子结构的起源进行细致的研究，从而更好的理解银河系的形成和并合历史。

The kinematic space in the solar neighborhood mainly consist of some arc substructures in large scale with some moving groups in small scale. Most of these substructures are caused by the nonaxisymmetric gravitational potentials such as bar and spiral arms and do not show coeval in chemical space. This project is engaged to detect chemical substructures in the solar neighborhood with the LAMOST spectroscopy and astrometric from Gaia. These chemical substructures have two origins, one is the collapse from the clusters, the other is the remnants from the dwarf galaxies. We will detect kinematic substructures in small scale using multiple dimension wavelet transform with coeval chemical properties. Also, substructures are directly detected in chemical space. The research on origin of these chemical substructures will help us understand the formation and merging histories of Milky Way.