Shocked H-2 and Fe+ dynamics in the Orion bullets

Observations of H-2 velocity profiles in the two most clearly defined Orion bullets are extremely difficult to reconcile with existing steady-state sh ock models. We have observed [Fe II] 1.644-mu m velocity profiles of select ed bullets, and H-2 1-0 S(1) 2.122-mu m velocity profiles for a series of p ositions along and across the corresponding bow-shaped shock fronts driven into the surrounding molecular cloud. Integrated [Fe II] velocity profiles of the brightest bullets are consistent with theoretical bow shock predicti ons. However, observations of broad, singly peaked H-2 1-0 S(1) profiles at a range of positions within the most clearly resolved bullet wakes are not consistent with molecular shock modelling. A uniform, collisionally broade ned background component which pervades the region in both tracers is incon sistent with fluorescence arising from the ionizing radiation of the Trapez ium stars alone.