基于LAMOST数据的M31和M33新天体搜寻及M31化学动力学性质研究

M31 is the nearest spiral galaxy and the largest galaxy of the Local Group. Accurate determinations of the chemical and kinematic properties of M31 are of great importance for the understanding of galaxy formation and evolution. As part of the LAMOST Spectroscopic Survey of the Galactic Anticentre, the LAMOST M31/M33 Survey has surveyed several hundreds square degrees of sky near M31 and M33. Being the only large, systematic spectroscopic survey in the world that covers M31 and M33 from the inner disks to the outer halo, the LAMOST M31/M33 survey provides an excellent opportunity of searching for new objects in M31 and M33, determining the kinematic and chemical properties of M31, and of revealing the formation and evolution history of M31. Based on the LAMOST data, we propose to: 1) carry out a systematic search and classification of new globular clusters, planetary nebulae and H II regions in M31 and M33; 2) collect all LAMOST spectra for these types of objects and the M31 integrated stellar spectra, determine their kinematic and chemical properties, including radial velocities and metallicities, as well as ages, and build large samples of them by combining with the data from previous works; 3) study the matter distribution, the velocity and metallicity distribution functions and the the assemblage history of M31.

M31是本星系群质量最大的成员和距离我们最近的大型旋涡星系，测量分析其化学动力学性质对理解星系的形成与演化至关重要。作为LAMOST反银心方向光谱巡天的一部分，LAMOST M31/M33巡天是目前世界上唯一完整覆盖了整个M31、M33及其近邻区域数百平方度天区的光谱巡天，巡天得到的海量光谱为系统搜寻和证认M31和M33里的新天体提供了巨大的发现空间，为精确测量M31化学动力学性质、揭示M31的起源与演化提供了重要的历史机遇。本项目拟基于LAMOST数据：1）开展M31和M33球状星团、行星状星云及电离氢区的系统搜寻与证认；2）收集所有LAMOST观测的以上几类天体，以及M31自身星族积分的光谱，对他们的运动学、化学参数（如视向速度、元素丰度等）以及年龄进行精确测定，结合文献数据构建相应样本；3）构建M31物质分布，刻画M31的速度与金属丰度分布函数，揭示M31的集成历史。

M31作为本星系群中最大的成员以及离我们最近的大型旋涡星系，是目前唯一一个可以进行完整全貌观测且精细研究的旋涡星系。LAMOST对M31/M33天区的光谱巡天观测完整覆盖了整个M31和M33及其近邻区域数百平方度的天区，获得了超过40万条光谱数据，为系统搜寻和证认M31和M33里的新天体，测量M31化学动力学性质、揭示M31的起源与演化提供了重要的历史机遇。我们基于LAMOST在M31和M33天区的光谱观测数据，结合国内外其他光谱、测光与天测数据：1）发现、证认了一批新M31和M33中各类天体候选体，包括新的行星状星云、电离氢区、超新星遗迹、共生星、年轻盘星团和球状星团等候选体；2）系统发展了从LAMOST的低色散星族积分光谱中准确地提取星族参数的方法，构建了具有运动学、年龄和金属丰度测量的M31星团等样本；3）探索了M31的速度场与金属丰度分布函数。