A 100 au-Wide Bipolar Rotating Shell Emanating From The HH
  212Protostellar Disk: A Disk Wind?
  HH 212 is a Class 0 protostellar system found to host a "hamburger"-shaped
dusty disk with a rotating disk atmosphere and a collimated SiO jet at a
distance of ~ 400 pc. Recently, a compact rotating outflow has been detected in
SO and SO2 toward the center along the jet axis at ~ 52 au (0.13") resolution.
Here we resolve the compact outflow into a small-scale wide-opening rotating
outflow shell and a collimated jet, with the observations in the same S-bearing
molecules at ~ 16 au (0.04") resolution. The collimated jet is aligned with the
SiO jet, tracing the shock interactions in the jet. The wide-opening outflow
shell is seen extending out from the inner disk around the SiO jet and has a
width of ~ 100 au. It is not only expanding away from the center, but also
rotating around the jet axis. The specific angular momentum of the outflow
shell is ~ 40 au km/s. Simple modeling of the observed kinematics suggests that
the rotating outflow shell can trace either a disk wind or disk material pushed
away by an unseen wind from the inner disk or protostar. We also resolve the
disk atmosphere in the same S-bearing molecules, confirming the Keplerian
rotation there.
