EXTREME-INFRARED (800-MU-M) POLARIMETRY AT THE JCMT OF THE W-75N-IRS-1 CLOUD

We have used the 15 m James Clerk Maxwell Telescope (JCMT) to obtain t he linear polarization and total continuum observations in the extreme infrared (at a wavelength of 800 mum) of the compact dust cloud W 75N -IRS 1. We observed a polarization of 0.7% +/- 0.24% at a position ang le of 55-degrees +/- 5-degrees, and an integrated total continuum flux density of 33.2 Jy over a mean (deconvolved) source size of 12''. Ext reme-infrared (i.e., submm wavelengths) polarization measurements can yield directly the magnetic field direction, a valuable tool for under standing the geometry and physics of the region involved. We use a dus t model to interpret the emission, inferring a mean gas density of 3 1 0(6) cm-3, and a magnetic field direction toward a position angle of 1 45-degrees. This direction is roughly parallel to the major axis of th e dense dusty cloud, and nearly perpendicular to the axis of a CO outf low from this cloud.