The magnetic field structure of the DR21 region

We present results of imaging polarimetry of the H-2 v = 1-0 S(1) line towa rds the outflow lobes of DR21. The polarization vectors are produced by dic hroic absorption in a medium of aligned grains and therefore delineate the direction of the magnetic field, projected on to the plane of the sky, alig ning those grains. It is argued that the polarization is dominated by grain s within the DR21 cloud. The magnetic held strength, estimated from the dis persion of position angles of the polarization vectors, is similar to 0.07 mG, which is not sufficient to play a significant role in either halting th e outflow or confining its lateral expansion. The polarimetry of the H-2 v = 1-0 S(1) line suggests that the magnetic fie ld is parallel to the outflow axis fur the eastern outflow lobe, whereas it appears twisted perpendicular to this axis for the western lobe, This pecu liar morphology for the magnetic field may imply the presence of either a t wo-component magnetic field along the line of sight or a complex, wound-up magnetic field.