A Magnetic Field Connecting the Galactic Center Circumnuclear Disk with Streamers and Mini-spiral: Implications from 850 mu m Polarization Data

Utilizing James Clark Maxwell Telescope 850 mu m SCUPOL dust polarization data, we investigate the configuration of the magnetic (B) field in the circumnuclear disk (CND) of the Galactic center. The SCUPOL data show a highly improved polarization coverage and resolution compared with earlier 100 mu m observations. The 850 mu m data have a resolution and coverage similar to previous 350 mu m polarimetry data. However, with a proper sampling on a 10 '' grid, we find that the 850 mu m data trace the morphological structures of the CND substantially better. Furthermore, because the 850 mu m trace the field deeper into the material near SgrA*, they represent the highest-resolution submillimeter probe to date of the CND magnetic field. The observed B-field morphology is well described by a self-similar axisymmetric disk model where the radial infall velocity is one-quarter of the rotational velocity. A detailed comparison with higher-resolution interferometric maps from the Submillimeter Array further reveals that the B-field aligns with the neutral gas streamers connecting to the CND. Moreover, the innermost observed B-field structure also appears to trace and align with the mini-spiral located inside the CND. This suggests that there is one underlying B-field structure that is connecting the CND with its streamers and the inner mini-spiral. An estimate of beta(Plasma) less than or similar to 1-based on the global B-field morphology that constrains the azimuthal-to-vertical field strength ratio of around 40 combined with a measurement of the azimuthal velocity indicates that the B-field appears dynamically significant toward the CND and also onwards to the inner mini-spiral.