利用LAMOST银河系低分辨率光谱巡天计划获得的海量光谱，筛选出银盘中大空间范围内的比较完备的红团簇巨星样本。利用光谱自动分析软件进行光谱处理并测得样本星的[Fe/H]、[α/Fe]结合由测光数据得到的位置信息，建立[Fe/H]、[α/Fe]的空间分布图像。通过分别研究金属丰度和α元素丰度梯度及比较不同银心距处的金属丰度分布函数，追溯银盘的演化历史，探寻可能存在的大规模恒星迁移的证据，从而检验目前受到广泛讨论的涉及盘状星系演化的恒星迁移理论。比较不同半径处的α丰度分布函数，研究不同半径处的恒星演化历史进而部分地验证一直比较流行的关于银盘形成的“inside-out”假说。建立并研究银盘中[α/Fe]-[Fe/H]空间统计图像，估计恒星的形成时间及恒星形成的强度，从观测的角度给银河系演化模型提供严格的约束，从而有助于理论工作者建立更加完善的银河系演化模型。

Based on the low-resolution spectra obtained by the LAMOST Galaxy survey (LEGUE), we will build a complete red clump sample of the Galaxy disk, which will cover a large range of Galactocentric distance. Using an automatic pipeline to reduce the low-resolution spectra of the red clump sample, and then the metallicities [Fe/H] and abundance ratio [α/Fe] will be determined. Combing the positions of sample stars, we will study the abundance gradients of the metallicity and α elements as well as the metallicity distribution function, trace the evolution history of the Galaxy disk, and test the theory of radial migration referring to the evolution of disk galaxies. Through comparing the α-abundance distribution functions with different Galactocentric distances, we expect to partly comfirm the “inside-out” growth of the Galaxy disk. Studying the statistic relations of [α/Fe]-[Fe/H] in a large space, we expect to answer the question that if the star formation rate has been episodic or rather steady, and give a firm constraint on the evolution model of the Galaxy.