Title：依托CSST巡天的强引力透镜高效搜寻与宇宙学应用前景
Speaker：陈云(中国科学院国家天文台)
Time:1月14日星期三上午10点
Location: 12楼会议室
Abstract：
中国巡天空间望远镜（CSST）是中国载人航天工程规划的大型空间天文望远镜，其2米口径与大规模巡天能力为天文观测提供了新的机遇。CSST巡天的重要科学目标之一是引力透镜效应的宇宙学应用及研究。引力透镜效应是广义相对论的重要预言之一，其中的强引力透镜现象在测量宇宙学参数和透镜天体性质等方面有其特有优势。本报告将系统介绍CSST巡天的基本情况，重点阐述如何依托其数据优势进行强引力透镜系统的有效搜寻，并对可发现的透镜系统数量作出预估。最后，报告将探讨强引力透镜在宇宙学中的应用前景及其科学价值。
CV：
陈云，中国科学院国家天文台副研究员，中国科学院大学主讲教师（兼职）；2007年本科毕业于大连理工大学物理系，2012年博士毕业于北京师范大学天文系，2010年-2011年在美国堪萨斯州立大学访问学习；2013年-2017年先后在中国台湾清华大学、中科院国家天文台从事博士后研究工作；2018年1月至今为国家天文台副研究员；主要研究涉及强引力透镜宇宙学、暗能量宇宙学、宇宙学探针优化及应用；荣获美国天文学会和IOP出版社共同评选的2019年“中国高被引作者奖”；2019年起深度参与中国巡天空间望远镜（CSST）项目的科学研究工作，主要贡献包括：参与撰写CSST科学白皮书，作为骨干成员参与强引力透镜早期科学准备。
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Title：Anisotropy of Satellite Galaxies: Contrasting Correlations with Central Galaxy, Host Halo, and Large-Scale Filament Structures
Speaker: Zhuoming Zhang (NAOC)
Time:1月14日星期三上午11点
Location: 12楼会议室
Abstract：
Connecting galaxies, halos, and filaments in sequence according to the formation order of the cosmic hierarchical structure is crucial for understanding the evolutionary processes of cosmic structures across different scales. Motivated by this, we present a comprehensive study focusing on three interrelated aspects: the scale-dependent anisotropy of satellite galaxy distributions, the correlations between this anisotropy and the morphologies of central galaxies, halos, and cosmic filaments, and the directional discrepancies among these three components.
Our results reveal that the major-axis correlation between central galaxies and halos, as well as the directional correlation between halos and filaments, are significantly dependent on halo mass. Furthermore, the anisotropy of satellite galaxy distributions shows scale-dependent correlations that are significant at the 3σ confidence level: it is only associated with central galaxy morphology on small scales (i.e., < 0.3R200c), exclusively related to halo morphology on the halo scale, and linked to cosmic filaments outside 2R200c. Notably, the conclusions regarding central galaxies, satellite galaxies, and halos are consistently significant across six different cosmological simulations.
CV：
Zhuoming Zhang is a Ph.D. candidate in cosmology at the National Astronomical Observatory of China (NAOC), enrolled in 2023. He received his Bachelor’s degree from Wuhan University. His research interests focus on three core areas: the satellite galaxy distribution within halo; the cosmological applications of large-scale structure (particularly galaxy clusters) via statistical analyses; and the investigation of dynamical dark energy models.