Gaia时代疏散星团外晕及延展结构的搜寻与认证

Gaia数据提供的高精度天体测量+测光数据解决了近距离星团的成员星认证问题，为疏散星团外晕结构的研究开拓了一个全新时代。借助于Gaia数据，最新的观测证据显示：疏散星团（尤其是年轻星团）除了已知的核心成份，其外围还存在着低密度的外晕成份。这一发现将有助于人们进一步理解不同星际环境中的星团/恒星形成过程，对研究太阳邻域的恒星形成历史、星团/恒星在巨分子云中的形成条件意义重大。目前，人们对星团外晕结构的认识和研究正处于起步阶段，迫切需要扩大具有外晕结构的星团样本，深入探讨有关疏散星团外晕性质的诸多重要问题。本项目瞄准这一研究热点，将基于Gaia数据对上百个疏散星团的外晕区域进行成员星搜寻和认证，并对其外晕结构进行参数化描述，建立首个包含外晕区域的疏散星团成员星表、以及包含外晕性质的疏散星团参数表，为进一步开展疏散星团外晕结构的统计研究、利用外晕成员星探讨疏散星团的形成和瓦解机制奠定基础。

The high-precision astrometric and photometric data provided by Gaia properly solves the problem of membership identification for most of the nearby open clusters. With the help of Gaia data, the latest observation results shows that there are low density halo components around the open clusters. This discovery shows great importance to the study of star formation history in the solar neighborhood and the formation conditions of stars in the giant molecular clouds. It will help us to further understand the star formation process in different interstellar environments. At present, understanding on the outer halo structure of open clusters are in the initial stage. It is urgent to expand the samples of open clusters with outer halo structure and study their properties. This project will systematically identify cluster members in the halo region for hundreds of open clusters, and parameterize the outer halo structures. We will establish the cluster member catalog and the cluster parameter catalog, including outer halo region. These catalogs will be used to further study the properties of outer halo, as well as the formation and evolution of open clusters.