Far-infrared CO line emission from Orion-KL

Far-IR and submillimeter observations of the hot, dense, shocked region surrounding the Kleinmann-Low nebula indicate that, in addition to a 2000 K component known from 2-micron observations, the hot shocked gas includes a large component at 750 K that dominates the 12-micron H2 line and far-IR CO line emission. The CO/H2 abundance ratio inferred for the shocked gas corresponds to 20 percent of the cosmic abundance of C existing in the form of CO. All the postshock gas, possibly even the plateau source, exists in the form of thin sheets perpendicular to the line of sight or in the form of clumps.