Sgr A* and Sgr A East: Intimate Life in the Galactic Center
  A hydrodynamic interaction between an old supernova remnant and a massive black hole is studied with the help of a high-resolution adaptive mesh refinement code. A series of multidimensional numerical models is obtained for a fixed distance between supernova explosion site and the black hole but different densities of the ambient medium. The interaction between the shell of the supernova remnant and the black hole results in a rapid increase of the emission from the vicinity of the black hole. Light curves of the gas heated by gravitational compression and hydrodynamical interactions are obtained assuming optically thin conditions. It is shown that the duration of the event and the peak luminosity critically depend on the density of the ambient medium. The model is applied to the data obtained by the Chandra satellite for the Galactic center. 
Tomek Plewa (1) and Michal Rozyczka (2) ((1) Center for Astrophysical   Thermonuclear Flashes, University of Chicago, (2) Co...