The nature of the broad molecular line emission at the Kleinmann-Low nebula

We have mapped the high-velocity emission in the wings of the CO line at the Kleinmann-Low infrared nebula. The half-power diameter is found to be 80 arcseconds. Upon analysis of the observed intensity profiles and the variations in angular size at different velocities, we conclude that a differentially expanding envelope, possibly the result of an explosive event, is the most likely explanation. The kinetic energy in the flow is 4 times 10 to the 47th ergs, based on a numerical model of the CO emission. The recently observed v = 1 to 0 radiation of H2 would arise from the shock front preceding the expanding gas.