ALMA Observations of the Very Young Class 0 Protostellar System HH211-mms: A 30 au Dusty Disk with a Disk Wind Traced by SO?

• Published in: The Astrophysical journal Vol. 863; no. 1; pp. 94 - 102
• Main Authors: Lee, Chin-Fei, Li, Zhi-Yun, Hirano, Naomi, Shang, Hsien, Ho, Paul T. P., Zhang, Qizhou
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 10.08.2018; IOP Publishing
• Subjects: accretion, accretion disks; Angular momentum; Angular velocity; Astronomical models; Astrophysics; Asymptotes; Atmosphere; Atmospheric models; ISM: individual (HH 211); ISM: jets and outflows; Outflow; Protostars; Rotating disks; Rotation; Space telescopes; stars: formation; Stellar evolution; Stellar models; Stellar winds; Wind
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/aad2da

HH 211-mms is one of the youngest Class 0 protostellar systems in Perseus, at a distance of ∼235 pc. We have mapped its central region at up to ∼7 au (0 03) resolution. A dusty disk is seen deeply embedded in a flattened envelope, with an intensity jump in the dust continuum at ∼350 GHz. It is nearly edge-on and is almost exactly perpendicular to the jet axis. It has a size of ∼30 au along the major axis. It is geometrically thick, indicating that the (sub)millimeter light-emitting grains have yet to settle to the midplane. Its inner part is expected to have transformed into a Keplerian rotating disk with a radius of ∼10 au. A rotating disk atmosphere and a compact rotating bipolar outflow are detected in SO NJ = 89 − 78. The outflow fans out from the inner disk surfaces and is rotating in the same direction as the flattened envelope, and hence could trace a disk wind carrying away angular momentum from the inner disk. From the rotation of the disk atmosphere, the protostellar mass is estimated to be 50 MJup. Together with results from the literature, our result favors a model where the disk radius grows linearly with the protostellar mass, as predicted by models of pre-stellar dense core evolution that asymptotes to an r−1 radial profile for both the column density and angular velocity.