Numerical hydrodynamics with a parallel integrated chemistry

Abstract

The interaction of a stellar jet with a molecular cloud is investigated using a computational approach in which the hydrodynamics, chemistry, and thermal behaviour are simultaneously and self-consistently integrated. The model incorporates the chemistry of 102 species whose abundances are coupled through a total of 1514 reactions. The dynamical and chemical structures are presented when the dynamics have achieved near steady-state. The results show that large variations in both density and temperature occur throughout the interaction region, and that these variations enable the identification of specific tracers of the various zones of interaction to be made. These tracer species are predicted to have detectable column densities and will have characteristic velocities and line profiles that should make them distinct from species in the ambient gas. Regions that should be chemically identifiable include the double shock structure at the jet head, the expansion of dense material from the jet head into the wake, the warm gas excited by the outer bow shock, and the mixing in the wake region.