Le 13 décembre 2013
Devaky Kunneriath
Astronomical Institute of the Academy of Sciences, Prague
Gas clouds are present in the centre of our galaxy, the Milky Way, where they orbit around the supermassive black hole, Sagittarius A*. Collisions between these clumps reduce their angular momentum, and as a result some of the clumps are set on a plunging trajectory. Constraints can be imposed on the nature of past accretion events based on the currently observed X-ray reflection from molecular clouds surrounding the Galactic centre.
I will discuss accretion of clouds in the context of enhanced activity of Sagittarius A* during the past few hundred years. These gas clouds bring material close to the horizon of the black hole on <=0.1 parsec scale. This scheme was also applied to the case of G2 cloud in the Galactic centre to obtain constraints on the core-less gaseous cloud model.