Dynamics of the Milky Way Bulge and its X-shaped Structure

主讲人 (Speaker): 沈俊太

主讲人单位 (Speaker's Institute): 中科院上海天文台

邀请人 (Invited by): 林伟鹏 教授

时间 (Time): 星期四, 2018/01/04 - 15:00 to 16:00

地点 (Location): 珠海校区海滨红楼17栋107会议室

摘要 (Abstract):

Recent years have witnessed a gradual paradigm shift in the formation and evolution of the Galactic bulge. Bulges were commonly believed to form in the dynamical violence of galaxy mergers. However, it has become increasingly clear that the main body of the Milky Way bulge is not a classical bulge made by previous major mergers, instead it appears to be a bar seen somewhat end-on. The Milky Way bar can form naturally from a precursor disc and thicken vertically by the internal firehose/buckling instability, giving rise to the boxy appearance. This picture is supported by many lines of evidence, including the asymmetric parallelogram shape, the strong cylindrical rotation, the existence of an intriguing X-shaped structure in the bulge, and perhaps the vertical metallicity gradient. I will also review modelling of the gas flow pattern induced by the Milky Way bar and spirals.

主讲人简介 (Speaker's CV):

中科院上海天文台研究员，国家自然科学基金委优秀青年基金获得者，英国皇家学会牛顿高级访问学者，中国科学院大学岗位教授。2005 年在美国罗格斯大学获得天体物理博士学位，其博士论文荣获2006年度罗格斯大学Plano博士论文奖（物理与天文系最佳博士论文）。2005年起作为独立博士后（Harlan J. Smith Postdoctoral Fellow）在德克萨斯大学奥斯汀分校进行研究工作。2009年回国工作并入选中科院“百人计划”，并且在2015年中科院百人计划终期评估中被评为优秀。主要研究方向为星系动力学和星系结构，包括银河系、旋涡星系、椭圆星系、超大质量黑洞、暗物质晕的结构演化及相互作用。他有多篇第一作者论文被国际天文学权威教科书《星系动力学》与《星系的形成与演化》，以及剑桥大学主编的天文参考书引述并配发原图。