AMMONIA OBSERVATIONS OF REGIONS WITH MOLECULAR OUTFLOWS

<p>Using the 37-m antenna of Haystack Observatory nine regions of molecular outflow (S187, AFGL 490, L1455, R Mon, AFGL 961, GGD 27-28, L723, AFGL 2591, and PV Cep) are observed in the (1,1) inversion transition line of NH3. NH3 is detected in six of these regions. Most of the observed ammonia condensations are unresolved with 1.4-arcmin resolution, so that neither the morphology nor the orientation with respect to the outflows could be determined. The only exception is the NH3 condensation in L1455, which is resolved and appears to straddle one of the blue CO lobes and the red CO lobe. There also appears to be some extended weaker NH3 emission that may be related to the CO outflow. The NH3 condensation in L723 shows a velocity gradient, which would be consistent with a rotating structure with its major axis aligned perpendicular to the outflow axis. High-angular-resolution observations of ammonia are required to test this suggestion. An H2O maser is detected that may be associated with the outflow from PV Cep. A statistical study of the sources with known molecular outflows shows that about 90 percent of the bipolar outflows are associated with high-density gaseous condensations. However, the association with the nonbipolar outflows is only about 50 percent. This result suggests an important role for the surrounding high-density gas on the collimation of the bipolar outflows.</p>