Interferometric mapping of magnetic fields: NGC 2071IR

Abstract

We present polarization maps of NGC 2071IR from thermal dust emission at 1.3 mm and from CO J = 2 -> 1 line emission. The observations were obtained using the Berkeley-Illinois-Maryland Association ( BIMA) array in the period 2002-2004. We detected dust and line polarized emission from NGC 2071IR that we used to constrain the morphology of the magnetic field. From CO J = 2 -> 1 polarized emission we found evidence for a magnetic field in the powerful bipolar outflow present in this region. We calculated a visual extinction A(v) approximate to 26 mag from our dust observations. This result, when compared with early single-dish work, seems to show that dust grains emit polarized radiation efficiently at higher densities than previously thought. Mechanical alignment by the outflow is proposed to explain the polarization pattern observed in NGC 2071IR, which is consistent with the observed flattening in this source.