潮汐瓦解事件的統一模型


Seminar:- A Unified Model for Tidal Disruption Events

In the centers of galaxies, scatterings between stars can kick a star into a fatal trajectory around the central supermassive black hole. The star approaches the black hole so closely that large tidal force can tear apart the star, and eventually half of the star is accreted onto the black hole producing a very luminous flare. This is called a tidal disruption event (TDE). Only in the past few years wide-field transient surveys have allowed us to get photometric and spectroscopic data on multiple candidate events. The recent breakthrough in TDE observations however have shone a spotlight on our incomplete theoretical understanding. While the physical processes in TDEs are universal, some observed TDEs radiated in thermal X-ray while others radiated in UV and optical. Moreover, only a small fraction of TDEs produced relativistic jets. The key theoretical component lacking so far in TDE studies is how the accretion and emission physics should be different from standard accretion scenarios, because in TDEs stellar debris is fed to the black hole at a rate beyond the Eddington limit. The speaker utilize state-of-the-art three-dimensional general relativistic radiation magneto hydrodynamics simulations to study the physics of this extremely dense, hot and luminous accretion. Besides showing general properties of super-Eddington accretion disks, outflows and jets, in this talk she will focus on showing how the viewing angle dependence of this accretion disk can provide a unification model for different classes of TDEs. 
 
時間:2017.11.21(二) 16:00
地點:香港大學 莊月明物理樓522室
講者:Dr. Jane Lixin Dai (Niels Bohr Institute, University of Copenhagen) 
語言:英語

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