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Public Seminar of RPg Student:
Revisiting the Rates and Demographics of Tidal Disruption Events

Speaker:Mr. Hong Tsun WONG
Affiliation:The University of Hong Kong
Date:June 15, 2021 (Tuesday)
Time:4:00 p.m.
Venue:Rm 522, 5/F, Chong Yuet Ming Physics Building, HKU
ZOOM Meeting ID: 915 1201 2981; Password: 914676


In the field of tidal disruption event (TDE), there exist significant discrepancies between the theoretical and observable demographics, especially regarding how the event rates depend on the masses of their host black holes (BHs).  The observed drop-off in TDE rates around massive BHs could be relatively well-explained by the direct plunge-in phenomenon from less massive stars.  However, the integrated causes of a similar trend around the lighter mass end remain uncertain.  In our work, we put forward a model in which ineffective circularization processes during the stream-stream collision could alleviate the aforementioned rate tension to a certain extent.  For TDEs around BHs of masses ~104 - 106M, the stellar debris streams dissipate orbital energy at a generally much lower circularization efficiency C than those with heavier host BHs.  Thus, the emissions from such TDEs might not be sufficiently powerful to produce high intrinsic luminosity to be detected by the current instrument.  We also investigate how different circularization efficiencies alter the β- and m*- distributions for a range of BH masses, and provide with the empirical fitting formulae for some of them. 

Anyone interested is welcome to attend.