2016MNRAS.460..627K

Outflowing motions, whether a wind launched from the disc, a jet launched from the protostar, or the entrained molecular outflow, appear to be a ubiquitous feature of star formation. These outwards motions have a number of root causes, and how they manifest is intricately linked to their environment as well as the process of star formation itself. Using the Atacama Large Millimeter/submillimeter Array (ALMA) Science Verification data of HL Tau, we investigate the high-velocity molecular gas being removed from the system as a result of the star formation process. We aim to place these motions in context with the optically detected jet, and the disc. With these high-resolution (∼1 arcsec) ALMA observations of CO (J=1-0), we quantify the outwards motions of the molecular gas. We find evidence for a bipolar outwards flow, with an opening angle, as measured in the redshifted lobe, starting off at 90deg, and narrowing to 60deg further from the disc, likely because of magnetic collimation. Its outwards velocity, corrected for inclination angle is of the order of 2.4 km s^-1.