Jet Propagation in Dense Media in the Early Universe


Universit├Ąt Heidelberg

The temporal evolution of large-scale magnetic jets will be simulated for young elliptical galaxies in the early universe at redshifts of 2--6. These jets, generated by the active nucleus of elliptical galaxies, propagate through a much denser and clumpier medium than they do in present-epoch radio galaxies. The interaction of the jet with the ambient gas leads to the observed extended Lyman-alpha emission of high-redshift radio galaxies. The nonrelativistic MHD-Code NIRVANA will be used to explore structure, kinematics and cooling of the jet material and the shocked intergalactic medium.Based on hydrodynamic results obtained so far, the effects of a magnetic field and different background media will be studied in 2D and 3D. In order to see the effects of magnetic fields in very light jets (density contrast eta < 10^-3), we need to decompose the computational domain into a few 10^6--10^8 cells and compute about some 10^6 timesteps due to the slow propagation of the jet head. We also plan to use the FLASH code in the future, which is capable of adaptive mesh refinement. This code runs best on a cluster as the CRAY Opteron cluster.