check
Dr. Rongfeng Shen,Racah Institute of Physics | The Racah Institute of Physics

Dr. Rongfeng Shen,Racah Institute of Physics

Date: 
Tue, 25/02/201412:30-13:30
Location: 
Kaplun building, Room No. 200
"Tidal Disruption of Stars by SMBHs: A Laboratory for Studying Transient Accretion Disks": During a stellar tidal disruption event (TDE), a transient disk forms as stellar debris returns to the disruption site and circularizes, whose super-Eddington accretion powers a bright flare, broadcasting the sudden awakening of a dormant super-massive black hole (SMBH). To date ~15 TDE candidates have been discovered and the number is bound to increase dramatically with the advancement of transient astronomy. I will describe a model for the evolution of the young TDE disk, by accounting for the time-dependent fallback rate, for the influence of wind losses in the early, super-critical stage, and for the possibility of thermal instability for accretion rates intermediate between the super-critical state and the standard Shakura-Sunyaev (SS) state. The model provides a dynamic basis for modeling TDE light curves. Application to the jetted TDE candidate Swift J1644+57 will be presented, whose apparent jet shutoff at t= 500 d we argue corresponds to a disk transition from the super-critical state to the SS state.