研究星系中心超大质量黑洞和宿主星系的共同演化是当前天体物理最前沿的课题之一。而黑洞增长和宇宙恒星形成密度均在红移2左右达到峰值,因此研究高红移黑洞增长和宿主星系的关系对于揭示共同演化背后的物理规律有着重要意义。本项研究将结合最新的Chandra深场（CDF-S和CDF-N）的X射线数据及Hubble空间望远镜的近红外数据，对一个数目较大的红移在0.5<z<2.5的X-ray AGN样本及宿主星系进行研究。我们主要着重于研究AGN和宿主星系的本征颜色（经红化改正）以及结构的关系。通过研究比较不同本征颜色、不同形态星系中AGN的比例，以及不同类型宿主星系中AGN性质的差别，我们试图从观测角度上对触发黑洞增长的物理机制和AGN对星系演化的反馈作用提出限制。

Studying the co-evolution of supermassive black hole (SMBH) and host galaxies is one of the most outstanding topics in astrophysics. Since both SMBH growth and cosmic star-formation rate peak at z=2, it is very important to study the relation between SMBH growth and host galaxy at high redshift to understand this co-evolution. In this project, we will combine deep X-ray data in the Chandra deep fields and the latest near-infrared data from Hubble Space Telescope to construct a relatively large X-ray AGN sample at 0.5<z<2.5, and study their relationships with host galaxies. We focus on the dependence of AGN properties on host galaxy color and structure. By comparing the fraction of AGNs in different hosts, and their properties, we can place observational constraints on the fueling mechanism of SMBHs,as well as how AGN affect galaxy evolution.