New Results on the Submillimeter Polarization Spectrum of the Orion Molecular Cloud

• Published in: arXiv.org
• Main Authors: Vaillancourt, J E, Dowell, C D, Hildebrand, R H, Kirby, L, Krejny, M M, H Li, Novak, G, Houde, M, Shinnaga, H, Attard, M
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 28.03.2008
• Subjects: Molecular clouds; Nebulae; Orion nebula; Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics; Polarimeters; Polarization; Wavelengths
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0803.4185

We have used the SHARP polarimeter at the Caltech Submillimeter Observatory to map the polarization at wavelengths of 350 and 450 micron in a ~2 x 3 arcmin region of the Orion Molecular Cloud. The map covers the brightest region of the OMC-1 ridge including the Kleinmann-Low (KL) nebula and the submillimeter source Orion-south. The ratio of 450-to-350 micron polarization is ~ 1.3 +/- 0.3 in the outer parts of the cloud and drops by a factor of 2 towards 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 a wavelength ~ 350 micron.