A rotating fast bipolar wind and disk system around the B[e]-type star
  MWC 922
  We present interferometric observations with the Atacama Large Millimeter
Array (ALMA) of the free-free continuum and recombination line emission at 1
and 3mm of the "Red Square Nebula" surrounding the B[e]-type star MWC922. The
unknown distance to the source is usually taken to be d=1.7-3 kpc. The
unprecedented angular resolution (up to ~0.02arcsec) and exquisite sensitivity
of these data unveil, for the first time, the structure and kinematics of the
emerging, compact ionized region at its center. We imaged the line emission of
H30a and H39a, previously detected with single-dish observations, as well as of
H51epsilon, H55gamma, and H63delta, detected for the first time in this work.
The line emission is seen over a full velocity range of ~180 km/s arising in a
region of diameter <0.14arcsec (less than a few hundred au) in the maser line
H30a, which is the most intense transition reported here. We resolve the
spatio-kinematic structure of a nearly edge-on disk rotating around a central
mass of ~10Msun (d=1.7 kpc) or ~18Msun (d=3 kpc), assuming Keplerian rotation.
Our data also unveil a fast (~100 km/s) bipolar ejection (a jet?) orthogonal to
the disk. In addition, a slow (<15km/s) wind may be lifting off the disk. Both,
the slow and the fast winds are found to be rotating in a similar manner to the
ionized layers of the disk. This represents the first empirical proof of
rotation in a bipolar wind expanding at high velocity (~100 km/s). (abridged)
