We report the 3D simulation of a hydrodynamic jet with parameters matched to the radio galaxy Cygnus A. For this simulation, a cylindrical grid is used in order to save computational resources. The jet is injected in pressure equilibrium into a King type cluster atmosphere with slight random modifications in order to break the symmetry. The jet is simulated as a bipolar outflow with the backflows allowed to interact with each other. Inward motion of the shocked external medium is observed in the symmetry plane, which is clearly visible in the plot of the derived bremsstrahlung emission. Based on these numerical results, we attempt to explain the spiral-like x-ray structures observed in Cygnus A. We propose that they are fingers of included and expanding shocked external medium. These results are extrapolated to higher redshift radio sources, which are thought to reside in even denser environments. Here, we propose that the same mechanism, as observed in this simulation, could explain the large amounts of cool line emitting gas within the hot radio bubble. Mainly due to hardware problems at HLRS, we were not able to compute the model upto the desired extention. The results are therefore preliminary.
|Title of host publication
|High Performance Computing in Science and Engineering '01
|Egon Krause, Willi Jager
|Place of Publication
|Published - 2002