AMBIPOLAR DIFFUSION AND FAR-INFRARED POLARIZATION FROM THE GALACTIC CIRCUMNUCLEAR DISK

We describe an implicit prediction of the accretion disk models constr ucted by Wardle & Konigl for the circumnuclear disk (CND) of gas and d ust near the Galactic center: supersonic ambipolar diffusion, an essen tial dynamical ingredient of the Wardle-Konigl disks, will cause the a lignment of dust grains because of a process described by Roberge, Han any, & Messinger. We calculate synthetic maps of the polarized thermal emission which would be caused by ambipolar alignment in the preferre d Wardle-Konigl model. Our maps are in reasonable agreement with 100 m u m polarimetry of the CND if we assume that the grains have shapes si milar to those of grains in nearby molecular clouds and that the CND c ontains a disordered magnetic field in energy equipartition with its o rdered field.