Title: Infrared Echoes of Tidal Disruption Events

Speaker: Ning Jiang, Department of Astronomy, University of Science and Technology of China

Host: Mouyuan Sun

Time: 14:30-16:30, Thursday, 

Location: Physics Building 552

Abstract: Tidal disruption event (TDE) happens when a star approaches too close to a supermassive black hole (SMBH). If the medium in the vicinity of the BH is dusty, the primary emission of the TDE (soft X-ray, UV, optical) will be reprocessed into the infrared (IR) band like an echo. The IR echoes of TDEs provide us a unique opportunity to probe the pc-scale dust (e.g., torus) in the galactic nuclei, which is otherwise extremely difficult to study. On the other hand, they can also help us unveil the obscured TDEs overlooked by optical/X-ray surveys.  In this talk, I will first introduce our discoveries of IR echoes of known TDEs utilizing the public multi-epoch WISE data. Then I will introduce our ongoing project focusing on Mid-Infrared Outburst in Nearby Galaxies (MIRONG), in hope of uncovering new TDEs in dusty environment by IR ehoes. We have constructed a large sample and carried out multi-wavelength (Optical, NIR, Radio, X-ray) follow-up observations. I will share some interesting results of the MIRONG project and highlight why the IR band is crucial for us to understand TDEs thoroughly.

Bio: 蒋凝，现任中国科学技术大学天文学系副研究员。2009和2015年毕业于中国科学技术大学，分别获学士和博士学位，攻读博士期间，在美国Carnegie天文台联合培养两年。随后在天文学系做博士后及特任副研究员，2019年4月被聘为副研究员。主要研究领域为黑洞潮汐撕裂恒星事件（TDE），中等质量黑洞， 活动星系核的大尺度环境以及时域天文相关的诸多问题。其作为主要完成人“首次发现黑洞潮汐撕裂恒星事件的红外回响信号”的工作入选2016年度中国十大天文科技进展。曾多次成功申请或使用包括Magellan,P200,CFHT, Shane,LCOGT等望远镜的观测。