A Highly Collimated, Young, and Fast CO Outflow in OMC-1 South

We present high angular resolution (~ 1''), sensitive CO(2-1) lineobservations of the region OMC1 South in the Orion Nebula made using theSubmillimeter Array (SMA). We detect the CO(2-1) high velocity outflow that wasfirst found by Rodriguez-Franco et al. (1999a) with the IRAM 30 m. Ourobservations resolve the outflow, whose velocity-integrated emission has adeconvolved width of 0.89'' \pm 0.06'' (490 AU) and a projected length of ~48'' (21,000 AU) with very high redshifted and blueshifted gas with velocitiesof about \pm 80 km/s. This outflow is among the most collimated (~ 3 degrees)and youngest outflows (600 yr) that have been reported. The data show that thiscollimated outflow has been blowing in the same direction during the last 600yr. At high velocities, the CO(2-1) outflow traces an extremely collimated jet,while at lower velocities the CO emission traces an envelope possibly producedby entrainment of ambient gas. Furthermore, we also detect for the first time amillimeter wavelength continuum source possibly associated with a class Iprotostar that we suggest could be the possible exciting source for thiscollimated outflow. However, the bolometric luminosity of this source appearsto be far too low to account for the powerful molecular outflow.Comment: Submitted to Astrophysical Journal (Letters