A MODEL FOR THE INTENSE MOLECULAR LINE EMISSION FROM OMC-1

We present a model which attributes the observed H/sub 2/ and CO line emission OMC-1 to a magnetohydrodynamic shock propagating into magnetized molecular gas. By requiring the shock to reporoduce the observed line intensities, we determine the shock speed to be v/sub s/roughly-equal38 km s/sup -1/ and the preshock density and (transverse) magnetic field to be n/sub H/roughly-equal7 x 10/sup 5/ cm/sup -3/, B/sub O/roughly-equal1.5 milligauss. The model is compared to observations of H/sub 2/, CO, OH, O I, and C I in emission and of CO in absorption. The shock gas may be detectible in H I 21 cm emission.