This week's Lunch Talk will be given by Zhenfeng Sheng (盛振峰), at 11:30AM Dec. 5th (Thursday) in the 19th-floor Observatory Hall (天文台报告厅).  He will present his work on the “变脸”活动星系核.

报告摘要：“变脸”活动星系核能几年的时标上呈现宽发射线产生（turn-on）或者消失（turn-off）的现象。这类极端变化的源对研究黑洞吸积物理、AGN宿主星系的性质以及AGN 与其宿主星系的共同演化有重要意义，是近几年该方向的研究热点。本次报告将介绍“变脸”AGN的研究进展以及我们在“变脸”AGN方面的工作。

You are welcome to join the discussion. We will provide boxed food from the faculty canteen. Please sign up via WeChat (Journal Club group) before Dec. 5th (Thur) 9 AM. The boxed food contains two meat dishes and two vegetable dishes by default, please add a * after your name if you want a vegetarian meal. Those who sign up but don't attend on time should pay a￥20 fee for the food, which will be used for future academic activities.