Astropizza

Mercoledì 7 novembre 2012, h. 13:00

Sala Jappelli

Uroš Kostic

University of Ljubljana

Faculty of Mathematics and Physics 

Tidal disruption of asteroids by supermassive black holes

Abstract:The compact radio source Sgr A* at the centre of our Galaxy harbours a super-massive black hole, and is therefore the nearest laboratory for testing the super-massive black hole astrophysics and environment. Since it is not an active galactic nucleus, it also offers the possibility of observing the capture of low-mass objects, such as comets or asteroids, that may orbit the central black hole. I will discuss conditions for tidal disruption of low-mass objects and predictions of the appearance and light curve of such events, as well as their relevance for the X-ray and infra-red flares detected in Sgr A*. The modelled light curves of such tidal disruption events bear marks of the strong gravitational field: tidal squeezing and elongation of the object, gravitational lensing, aberration of light, and Doppler effects. I will show that this model is able to reproduce and fit X-ray flares.