New results on the submillimeter polarization spectrum of the Orion Molecular Cloud

We have used the SHARP polarimeter at the Caltech Submillimeter Observatory to map the polarization at wavelengths of 350 and 450 mu m in a similar to 2 ' x 3 ' region of the Orion Molecular Cloud. The map covers the brightest mm region of the OMC-1 ridge including the Kleinmann-Low (KL) nebula and the submillimeter source Orion-south. The ratio of 450 to 350 mu m polarization is similar to 1.3 +/- 0.3 in the outer parts of the cloud and drops by more than mm a factor of 2 toward KL. The outer cloud ratio is consistent with measurements in other clouds at similar wavelengths and confirms previous measurements placing the minimum of the polarization ratio in dusty molecular clouds at lambda similar to 350 mu m.