Energetic activity in a star-forming molecular cloud core - A disk constrained bipolar outflow in NGC 2071

Abstract

The discovery of an extended, high-velocity molecular outflow associated with the infrared sources in NGC 2071 is reported. High-velocity CO emission from this star-forming molecular cloud core can be traced over a region 4' in diameter and detected over a velocity range of 70 km s/sup -1/. The flow is bipolar; the blueshifted CO emission is displaced to the northeast, while the redshifted emission is displaced to the southwest. Observations in the 98 GHz transition of CS reveal a ridge of dense gas oriented orthogonal to the high-velocity flow axis. A systematic velocity gradient seen in the CS line core suggests that the ridge is a dense, rotating disk centered on the IR source. The disk may be responsible for collimating a spherically symmetric wind originating near the IR source into the bipolar flow observed in the high-velocity CO line wings. The high-velocity CO line wings are modeled as beam diluted emission from clumps or filaments with /sup 12/ CO optical depths close to unity and a small filling factor. The clumps may be either objects ejected from the vicinity of the central infrared source or shocked gas at the front where a higher velocity but invisible flow encounters ambientmore » cloud material.« less