Studying Dust Properties, Grain Alignment And Magnetic Field Structure With Multi-Wavelength Submillimeter Polarization

Polarization dust emission, from non-spherical grains aligned with magnetic field lines, is a key tracer in the study of interstellar magnetic fields. However, interpreting polarization is a nontrivial task. Polarization angles only provide a 2D picture of the 3D interstellar magnetic field structure, and the polarization fraction depends on several factors that are difficult to disentangle. One way of breaking these degeneracies is to study polarized emission at multiple wavelengths. I show the results of a pilot study of star-forming region N2071 that combines 850 $\mu$m polarimetry from the BISTRO JCMT large project with 154 $\mu$m and 214 $\mu$m polarimetry from the HAWC+ instrument on SOFIA. We observe a variation of polarization angle with wavelength which is likely a result of a change in magnetic field orientation on the line of sight, although a change in the alignment regime could be an alternative explanation. Furthermore, the ratio of polarizations at 154 $\mu$m and 214 $\mu$m could not be reproduced using single dust models, which suggests the need for heterogeneous cloud models.