The discovery of the youngest molecular outflow associated with an intermediate-mass protostellar core, MMS-6/OMC-3

Abstract

We present subarcsecond resolution HCN(4-3) and CO(3-2) observations made with the Submillimeter Array, toward an extremely young intermediate-mass protostellar core, MMS6-main, located in the Orion Molecular Cloud 3 region (OMC-3). We have successfully imaged a compact molecular outflow lobe (1000AU) associated with MMS6-main, which is also the smallest molecular outflow ever found in the intermediate-mass protostellar cores. The dynamical timescale of this outflow is estimated to be ≤100yr. The line width dramatically increases downstream at the end of the molecular outflow (Δv 25kms-1) and clearly shows the bow-shock-type velocity structure. The estimated outflow mass (10-4 M ) and outflow size are approximately two to four orders and one to three orders of magnitude smaller, respectively, while the outflow force (10-4 M kms-1yr-1) is similar, compared to the other molecular outflows studied in OMC-2/3. These results show that MMS6-main is a protostellar core at the earliest evolutionary stage, most likely shortly after the second core formation. © 2012. The American Astronomical Society. All rights reserved..