云台学术报告 2022年8月8日(星期一)上午1000-1130 主楼427会议室

【学术报告】 ～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～ 报告题目：Elliptical accretion disk as a model for tidal disruption events 报告人：刘富坤 教授 报告人单位:北京大学 报告时间：2022年8月8日(星期一)上午10:00-11:30 报告地点：主楼427会议室 报告语言: 中文 报告摘要： ～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～ A star would be tidally ripped, when it closely passes by a supermassive black hole (SMBH). After the tidal disruption, about half of the stellar debris becomes bound and falls back to the SMBH. In the canonical model, the kinetic energy of the fallback stellar debris is dissipated efficiently by self-crossing shocks but the angular momentum is nearly conserved. A compact circular accretion disk forms and radiate mainly in extreme-UV wavebands and the soft X-rays. However, the canonical model is challenged by the observations of the stellar tidal disruption events (TDEs) discovered in the optical/UV wavebands. A revision is needed. Recent numerical simulations suggested that the self-crossing shocks can efficiently not only dissipate the kinetic energy but also transfer the angular momentum of the fallback stellar debris. A highly elliptical accretion disk is expected. Inspired by the recent We recently developed an elliptical accretion disk model for TDEs and well explained the observations of the optical/UV TDEs based on it. In this talk, after briefly reviewing the main observations of TDEs, I will introduce the elliptical accretion disk model and show the well consistence of the model expectations and the observations of TDEs. ～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～～ 本通知也可以在云台学术报告网页看到： http://www.ynao.cas.cn/xwzx/xstg/ 申请安排学术报告的同事请参见台学术报告管理办法： http://www.ynao.cas.cn/xwzx/xstg/gzzd/ 云台邀请团组：南方天文观测基地、云南天文台青促会小组 邀请方联系人：张居甲，18288271003 8月7日