Title: The precession and circularization of stellar debris stream in tidal disruption events

Speaker: 申荣锋（Sun Yat-Sen University）

Time: 10:00 AM, Fri, 6 Nov 2026

Location:Lecture Hall, 3rd floor

Invited by: Hengxiao Guo

Abstract:In a tidal disruption event (TDE), the stellar debris after disruption falls back toward the black hole in the form of an elongated stream. It must undergo orbital energy dissipation (i.e., circularization) before it can accrete onto the black hole in the form of a disk. Therefore, the efficiency of the circularization process not only affects timescale of the accretion process, but also determines its own corresponding radiation signatures. Taking intermediate-mass black hole TDEs as a study case, I will discuss the respective radiation signatures of the circularization and accretion processes, as well as their correspondence to the optical and X-ray light curve behaviors in several observed events. In addition, when a TDE occurs around a Kerr black hole, the circularization process and the onset of disk accretion will be significantly delayed by the Lense-Thirring precession. We have studied the influence of the cumulative precession of the debris stream on the later disk precession in this scenario.

CV: Rong-Feng Shen obtained his PhD in University of Texas at Austin in 2010, and worked as postdoctoral fellows at University of Toronto (2010-2013) and Hebrew University at Jerusalem (2013-2015). He joined the School of Physics and Astronomy, Sun Yat-Sen University as a faculty member in 2015.