题目: Gas dynamics and planet formation in the outer protoplanetary disks

报告人：白雪宁 清华大学 教授

地点：紫金港校区西区海纳苑8幢324教室

时间：2023.05.26（周五），下午13:30

Abstract: The prevalence of disk substructures, as a major observational revolution over the past few years, calls for new perspectives in our understanding of the gas dynamics of protoplanetary disks and planet formation. I will start by introducing the central role of magnetic field in driving disk dynamics and evolution, and the framework of magnetized disk winds. By focusing on the most observable disk outer regions, I will first show that magnetism in outer disk conditions leads to weak turbulence and stochastic magnetic flux concentration that naturally leads to the formation of ring-like substructures. Next, I will show that such weakly turbulent dust rings can be natural sites for planetesimal formation, despite that the streaming instability is unlikely to operate. Finally, I will present global simulations of planet-disk interaction in weakly turbulent windy disks, where magnetic flux concentrates in the planet-induced gap that drives fast flow through the gap, leading to distinct features in gap morphology and gas kinematics.

Bio: Prof. Xuening Bai graduated from Tsinghua University with a B.S. in mathematics and physics in 2007, and obtained his PhD in astrophysics from Princeton University in 2012. He was a Hubble Fellow and Institute for Theory and Computation (ITC) fellow at the Harvard-Smithsonian Center for Astrophysics from 2012-2017. He joined the faculty at the Institute for Advanced Study, Tsinghua University in 2017, and is jointly affiliated with Department of Astronomy. He is a theoretical and computational astrophysicist. His research group studies protoplanetary disks and planet formation, as well as several aspects of plasma astrophysics especially on cosmic-ray acceleration and transport, and develops computational tools for related applications.

欢迎老师和同学参加！