类星体成协吸收系统（吸收线红移约等于发射线红移的系统）是了解类星体周围或中心附近气体分布、物理条件、气体动力学过程的重要手段，但目前仍缺少大样本类星体成协吸收系统。Sloan Digital Sky Survey （SDSS）已获得超过50万个类星体光谱数据，约10%的光谱将出现成协吸收系统。首先，本项目将利用SDSS类星体光谱数据，系统分析Mg II和C IV成协吸收系统，预计将获得超过5万个成协吸收系统。其次，本项目将利用成协吸收系统，研究成协吸收体在类星体周围分布，研究分布在类星体视线方向和垂直视线方向的差异以及引起差异的根本原因，以及研究分布与类星体外流、中心电离辐射、周围星系成团特征的关系。第三，本项目将研究成协吸收体的吸收、消光红化作用对类星体中心电离辐射特征的影响，以及成协吸收系统特征与类星体射电、红外、光学、紫外、X-ray等多波段辐射特征的相互影响和相互关系。

Quasar associated absorption line systems (AAS, the systems with absorption line redshifts being similar to emission line redshifts) are an important tool to investigate the distributions, physical conditions, dynamical mechanisms of gas around quasars. While, no large sample of quasar AAS is available up to now day. The Sloan Digital Sky Survey (SDSS) has obtained more than 0.5 million quasar spectra, of which about 10% quasar spectra will be detected at least one obvious AAS. Firstly, using the quasar spectra of the SDSS, we will identify and measure Mg II and C IV AAS, and we will get more than 50,000 AAS. Secondly, we will investigate the distribution of associated absorbers around quasars, study the difference of the AAS distributions and its origins between along and perpendicular to the quasar sightlines, and investigate the relationships between the AAS distributions and the intrinsic characteristics of quasar outflows, ionized radiations and clustered galaxies around quasars. Thirdly, we will investigate the roles that the absorption, extinction and reddening of the AAS would play on the characteristics of the quasar ionized radiations, and investigate the interactions and relationships between properties of the AAS and multi-bands radiations of quasars.