Abstract
We present the polarization map of CO J = 3-2 line in the molecular outflows launched from NGC1333 IRAS 4A protostellar core. The spectral line polarization arises from the Goldreich-Kylafis effect, which predicts that the polarization could be either parallel or perpendicular to the magnetic field direction. To resolve the orientation of CO polarization to magnetic field direction, comparisons between CO polarization and dust polarization are made with the knowledge that the dust polarization is perpendicular to the magnetic field. We found that within the IRAS 4A dusty envelope, the CO J = 3-2 polarization directions are mostly perpendicular to the dust polarization, suggesting that the CO polarization is parallel to the magnetic field. The directions of the CO polarization appear to vary smoothly from the dust continuum to the red-shifted lobe of the outflows without any abrupt changes, implying that the CO polarization remains parallel to the magnetic field direction in the outflows. We speculate that a helical field may be wrapping around the outflows, which is consistent with the theoretical expectations for outflows associated with a rotating disk. Considering that the CO J = 3-2 polarized emission is mainly contributed from low velocity component of outflows and the polarization detections distribute around the wall of outflows, the magnetic field revealed by CO J = 3-2 polarization may be at the wall of outflows and associated to the interaction between envelope and outflows. Additional observations of line polarization from different density traces are needed to test our proposed scenario.