ALMA observations of the very young Class 0 protostellar system HH
  211-mms: a 30-au dusty disk with a disk-wind traced by SO?
  HH 211-mms is one of the youngest Class 0 protostellar systems in Perseus at
~ 235 pc away. 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 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. 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
M_Jup. 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.
