SUBMILLIMETER POLARIMETRY OF CLASS-0 PROTOSTARS - CONSTRAINTS ON MAGNETIZED OUTFLOW MODELS

Polarized 800 mu m emission from magnetically aligned dust grains has been detected in five protostars. Previously, only two such detections had been made. All of these protostellar sources have associated bipo lar outflows and presumably also circumstellar disks. We find that the angle between the deduced magnetic field direction and the outflow ax is, Delta theta, appears to be correlated with the angle between the l ine of sight to the observer and the outflow direction, theta(los). If the outflow is in the plane of the sky, then the deduced magnetic fie ld tends to be perpendicular to the outflow, and if the outflow is ang led toward the observer, then the magnetic field tends to lie parallel to the outflow. Various magnetic field geometries could explain this trend. In addition, the 800 mu m percentage polarization, p, appears t o be inversely correlated with the ratio of L-bol/L-1.3 mm, which is a measure of the evolutionary stage of the source, and with the bipolar outflow opening angle, which also increases as a source evolves, and it appears to be correlated with source distance. We interpret these r esults as indicating that the observed magnetic field is more ordered in younger sources. The most likely interpretation of the distance cor relation appears to be that the field is more ordered in more massive sources. As yet, there are no theoretical models for the magnetic fiel ds around protostars that can fully explain all of these correlations.