Dissociative Shocks in the Neighborhood of Orion IRc2 Traced with Atomic Carbon

We present Caltech Submillimeter Observatory 10" resolution maps of the 3P2-->3P1 line of neutral atomic carbon (809.3435 GHz) and the J=7–6 line of CO (806.6518 GHz) covering a region of 2'x4'.5 around Orion IRc2 in the BN/KL Nebula. The two lines were observed with the same receiver simultaneously, and therefore\udthe two maps have zero relative pointing error. The atomic carbon (C I) emission does not peak toward the IRc2 position and displays a very different spatial distribution with respect to most molecular species. Moderately strong red wings are detected in C I around the region defined by the high-velocity CO gas with a spatial\uddistribution that delineates a shell of ∼20" radius. We propose that CO dissociation in the J-type shocks produced\udby the interaction of the IRc2 outflows with the surrounding quiescent gas could play a significant role in this\udenhancement of atomic carbon in that shell.This work has been supported by Spanish DGES and PNIE grants AYA2000-1784, ESP2001-4516, and AYA2003-2785 and by US NSF grant AST 99-80846.Peer reviewe