题目：What can we learn from the structural diversity of (extrasolar) planets

　　报告人：Shangfei Liu

　　Rice University / Los Alamos National Laboratory

　　摘要：The conventional core accretion scenario predicts that the final assembly of terrestrial planets involves catastrophic collisions between lunar to Mars-sized planetary embryos. Gas giant planets are also likely to experience giant impacts during and after disk dispersal. From the observational point of view, close-in exoplanets exhibit a huge diversity in their bulk densities. Several post-formation processes have been proposed for explaining the origin of the compositional diversity. However, none of them can satisfactorily account for the whole population. In this talk, I will try to argue such a diversity is a natural consequence of giant impacts at the final stage of planet formation. I will present the results of our latest three-dimensional hydrodynamic simulations of planetary collisions and their implications for the formation of some exotic exoplanet systems as well as icy planets in the Solar System.

　　Finally, we show results of a series of hydrodynamical and N-body simulations and present a new scenario which may help explain the formation and past evolution of (at least) some of these systems.

　　时间：2015年12月25日 星期五 上午10:30

　　地点：（北京西路2号）紫台大楼517会议室

欢迎大家积极参加！

　　                                               紫金山天文台学术委员会