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.
Categories: astro-ph.GA