2005MNRAS.357.1370S

The bandpasses for Spitzer images contain numerous molecular hydrogen emission lines. With the additional complication of the non-uniform spectral response, it is necessary to calculate model images in order to analyse observations of molecular outflows. We employ three-dimensional hydrodynamic simulations of a range of dense supersonic molecular jets, including various degrees of velocity pulsation and precession, to demonstrate how the observed structure depends on the band. Features in band 1, which is dominated by emission from vibrational levels, are even more concentrated than in K-band images. In contrast, bands 2-4 are dominated by rotational lines and bow shock wings appear extended. Especially in band 4, broken cavity walls can be detectable. An initial comparison with Spitzer data is made.