【学术报告】

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报告题目：Probing black hole mass, spin and general relativistic effects in tidal disruption flares

报告人：余文飞教授(Prof. Dr. Wenfei Yu)

报告人单位：上海天文台(Shanghai Astronomical Observatory)

报告时间：2019年6月5日（星期三）下午3:00—4:00

报告地点：主楼427会议室

报告语言：中文

报告摘要： 

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When normal stars run close enough to previously dormant supermassive black holes (SMBHs) at the centers of normal galaxies, they would be entirely or partly disrupted due to the tidal force of the central SMBH, leading to the so-called tidal disruption events (TDEs). Part of the debris of the disrupted stars will be accreted by the SMBHs afterwards and generate accretion flares usually in the optical, UV band, and X-ray band. These flares provide great opportunities to probe those dormant SMBHs at the centers of normal galaxies, which represent the majority of SMBHs in our universe. Here we show predicted relativistic line features and the spectral line evolution expected to occur during the accretion phase of the debris material. These spectral line features are imprints of the mass and the spin of the previously dormant SMBHs while bring clues to the geometry and properties of the accretion flow, providing unique probes of the general relativistic Lense-Thirring precession and the Bardeen-Petterson effect expected in TDEs.  In the next decade, sensitive wide field-of-view monitoring in the radio band with the SKA or the ngVLA will be able to detect jet activities due to the accretion of the debris flow of disrupted stars onto the SMBH at the very early stage when the mass accretion rate onto the SMBHs is very low, allowing us to probe mass and spin of those dormant SMBHs and detect general relativistic effects through follow-up X-ray observations. 

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Dr. Wenfei Yu is leading the observational high energy astrophysics group at Shanghai Astronomical Observatory. Making use of both space and ground observational facilities such as XMM-Newton, Swift, HXMT, and JVLA, etc., as well as publicly available X-ray all-sky monitors, his research has been focused on phenomena in X-ray binaries in our Galaxy and various high energy and multi-wavelength transients in which accretion physics and relativistic astrophysics are to be addressed. He is a core member of the scientific working groups of the future space missions such as the eXTP and the SVOM, and next generation ground facilities such as the SKA, which are critical to the topic of his talk. 

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云台邀请团组：大样本恒星演化研究组、中国科学院天体结构与演化重点实验室、云南天文台学术委员会

邀请方联系人：韩占文(0871-63920139)

6月3日