At 0.5 pc scale, the B field is uniform across the envelope, indicating that the B field is dominant over turbulence and the envelope is stable at this scale. At 0.02 pc scale, the B field lines are shaped by gravity. A hourglass-shape B field morphology is resolved toward the ultracompact HII region e2 and possibly also toward e8. These results indicate that the role of B field varies in different scales. (Tang et al. 2009, ApJ, 700, 251) |