Discovery of the Youngest Molecular Outflow associated with an
  Intermediate-mass protostellar Core, MMS-6/OMC-3
  We present sub-arcsecond resolution HCN (4-3) and CO (3-2) observations made
with the Submillimeter Array (SMA), toward an extremely young intermediate-mass
protostellar core, MMS 6-main, located in the Orion Molecular Cloud 3 region
(OMC-3). We have successfully imaged a compact molecular outflow lobe (~1500
AU) associated with MMS6-main, which is also the smallest molecular outflow
ever found in the intermediate-mass protostellar cores. The dynamical time
scale of this outflow is estimated to be <100 yr. The line width dramatically
increases downstream at the end of the molecular outflow ({\Delta}v~25 km
s^{-1}), and clearly shows the bow-shock type velocity structure. The estimated
outflow mass (~10^{-4} M_{sun}) and outflow size are approximately 2-4 orders
and 1-3 orders of magnitude smaller, while the outflow force (~10^{-4} M_{sun}
km s^{-1} yr^{-1}) is similar, as compared to the other molecular outflows
studied in OMC-2/3. These results show that MMS 6-main is a protostellar core
at the earliest evolutionary stage, most likely shortly after the 2nd core
formation.
