报告题目：Stride Across the Distance Ladder

　　报告人：李鑫（紫台研究生）

　　摘要：Distance measurements for extragalactic objects are a fundamental problem in astronomy and cosmology. In the era of precision cosmology, we urgently need better measurements of cosmological distances to observationally test the increasing H0 tension of the Hubble constant measured from different tools. Using spectroastrometry , GRAVITY at The Very Large Telescope Interferometer successfully revealed the structure, kinematics and angular sizes of the broad-line region (BLR) of 3C 273 with an unprecedentedly high spatial resolution. Fortunately, reverberation mapping (RM) of active galactic nuclei (AGNs) reliably provides linear sizes of their BLRs . Here, we report a joint analysis of spectroastrometry and RM observations to measure AGN distances.

　　参考文献：Wang, J.-M. et al. 2020, Nat Astron., 4, 517

　　时间：2020年12月24日星期四中午12:00

　　地点：紫台仙林3-402会议室