A Bipolar Outflow: L1641-North and Its Ambient Dense Cloud

This paper reports on high angular resolution observations of J = 1-0 emission from CO, HCO(+), and HCN in L1641-north, a bipolar outflow newly found during an unbiased CO(J = 1-0) survey made with the Nagoya 4-m radio telescope. The high-velocity CO wings show a clear bipolar structure and are localized within 0.2 pc of a central infrared source IRAS 05338-0624. The outflow is associated with a dense cloud that is significantly elongated in the same direction as the outflow axis, contrary to what is expected for disk collimation of the bipolar outflow. This suggests that large interstellar gas disks are not always necessary for collimation. The collimation in L1641-north is likely made very close to the outflow center; i.e., within about 0.02 pc of the driving source.