Hydrodynamical simulations of the jet in the symbiotic star MWC 560. II. Simulations beyond density balance

Context: .In the first paper of this series, we presented hydrodynamical simulations with radiative cooling of jet models with parameters representative of the symbiotic system MWC 560. These were jet simulations of a pulsed, initially underdense jet in a high-density ambient medium. They were stopped when the jet reached a length of 50 AU. There, however, a transition of the initially underdense jet towards an overdense jet should occur, which should result in changed kinematics. A few minor differences between the models and the observations were thought to be solved by a model with an increased jet density during the pulses which was calculated only with purely hydrodynamical means in the former paper.
Aims: .Therefore, we describe two hydrodynamical simulations with cooling beyond this density balance, one with the same parameters as model i in Paper I (now called model i´), which was presented there with and without cooling, and the second with higher gas densities in the jet pulses (model iv´).
Methods: .Hydrodynamical simulations, with a further approximated cooling treatment compared to Paper I, were used to be able to enlarge the computational domain.
Results: .The transition causes changes in the expansion of the cocoon and therefore the morphology of the jet, e.g. a larger radial width of the jet knots. We investigate the radiation properties of the jets, the bremsstrahlung and optical emissivities, integrated emission maps, and synthetic absorption line profiles.
Conclusions: .The conclusion that the high observed velocities in CH Cygni, R Aquarii, and MWC 560 favor the models with cooling is unchanged by the transition. The observed parallel features in R Aquarii can be produced by the internal knots or by a variable dense radiative shell of shocked ambient medium. The absorption line profiles show that the real parameters in MWC 560 are closer to model iv´ than to model i´.