报告题目：Galactic Archaeology in the Era of Gaia and Large Spectroscopic Surveys

　　报告人：袁珍（博士）

　　报告人简介：Dr. Yuan graduated from physics department of Nanjing University in 2009, and received her PhD in physics from University of Minnesota in 2015, where she developed deep interests in dwarf galaxies in the local universe. She was a postdoc in Shanghai Jiaotong University, and Shanghai Astronomical Observatory as LAMOST fellow, from 2015 to 2020, where she transited to search for the debris of dwarf galaxies in the Milky Way using the revolutionary astrometric data from Gaia satellite. She will join Observatoire Astronomique de Strasbourg in April 2021 to pursue her career in Galactic Archaeology. Dr. Yuan will take part in the Pristine, WEAVE surveys led by European partners, and also leads the dwarf galaxy searching project in the Chinese Space Telescope survey.

　　摘要：As the witnesses of the high redshift universe, dwarf galaxies, especially the low-mass ones, carry the imprint of essential physical processes, from the formation of the first stars to the formation of the first galaxies that shaped the universe into the one we observe today. The Milky Way stellar halo provides us with a unique and readily accessible reservoir of stellar debris from ancient dwarf galaxies merged in the past. In the current era of Gaia and large spectroscopic surveys, such as LAMOST and forthcoming WEAVE and 4MOST, the full 6-dimensional kinematic information is available for millions of nearby stars for the first time.

　　In this talk, I will report a newly discovered stream (LMS-1) from a disrupted low mass dwarf galaxy, which is the third stream contributed to the inner stellar halo, after the Sagittarius and Cetus Streams found 10 - 20 years ago, all of which have fairly polar orbits. This raises the question that if the disrupted dwarf galaxies along polar orbits can maintain relatively coherent stream structures, similar to the formation mechanism of the vast polar structure of satellite galaxies.

　　报告时间：2021年03月12日 ，上午10点（周五）

　　报告地点：紫台5-516会议室

　　邀请团组：星系宇宙学与暗能量研究

欢迎大家参加！

紫金山天文台学术委员会