Modelling jet-driven molecular outflows

We have investigated the basic physical properties of the outflow that is created by a supersonic jet in a dense molecular cloud. We show that the dynamics of the interaction is strongly controlled by the rapid cooling of the post-shock gas at the head of the jet. The velocity of the gas is high in the vicinity of the jet head, but decreases rapidly as more material is swept-up. This type of outflow produces extremely high velocity clumps of post-shock gas which resemble the features seen in outflows. We also show that momentum transfer in bow shocks is more important than entrainment in high Mach number jets, as found in the protostellar environment.