The winds from HL Tau. Issue 1 (28th April 2016)

• Record Type: Journal Article
• Authors: Klaassen, P. D.; Mottram, J. C.; Maud, L. T.; Juhasz, A.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 460:Issue 1(2016)
• Page Start: 627
• Page End: 633
• Publication Date: 2016-04-28
• Subjects: techniques: interferometric -- stars: formation -- stars: winds, outflows -- ISM: jets and outflows -- submillimetre: ISM; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stw989
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: 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 90°, and narrowing to 60° 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 .