Discovery of the Youngest Molecular Outflow associated with an Intermediate-mass protostellar Core, MMS-6/OMC-3

TL;DR

This study reports the discovery of the youngest and smallest molecular outflow associated with an intermediate-mass protostellar core, MMS-6/main, revealing an extremely early stage of star formation in the Orion Molecular Cloud 3 region.

Contribution

The paper presents high-resolution observations of a compact, young molecular outflow in an intermediate-mass protostellar core, demonstrating an outflow with the shortest dynamical timescale and smallest size recorded.

Findings

Outflow age estimated to be less than 100 years.

Outflow size is approximately 1500 AU, the smallest in similar cores.

Outflow force is comparable to larger outflows despite smaller size.

Abstract

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.