Numerical Simulation of Weakly Magnetized Propagating Slab Jets

Abstract

Simulations of weakly magnetized propagating slab jets have been performed for a range of jet velocities. The magnetic field is introduced in the form of closed field loops and a local emissivity is computed in a cross section through the infinite slab. The use of slab geometry allows study of non-axisymmetric effects. The jet is driven by a periodic sinusoidal oscillation in time of the angle of the jet’s velocity relative to the z-direction at the inlet. This driving mechansim excites the sinusoidal modes. These modes are the 2-D analog of helical modes. At early times the jet maintains approximate axisymmetry within a backflowing cocoon. At later times when the jet has penetrated farther into the external medium the symmetry is broken by sideways oscillation which destroys the jet’s directionality and the jet “flaps” within a growing lobe.