THE MOLECULAR CORES IN THE L1287, AFGL-5142, AND IRAS 20126+4104 REGIONS

The NH3 (J, K) = (1, 1) and (2,2) line emission was mapped toward thre e regions with molecular outflows, L1287, AFGL 5142, and IRAS 20126+41 04, using the Effelsberg 100 m telescope. Additional (CO)-O-18 (J = 2 --> 1) and CS (J = 3 --> 2) observations of L1287 were carried out wit h the IRAM 30 m telescope. For the three regions, the high-density mol ecular core, as traced by the ammonia emission, peaks very close to th e position of the proposed powering sources of the outflows. In AFGL 5 142 we favor the radio continuum source proposed by Torrelles et al. ( 1992b) as the powering source of the outflow. The molecular cores best resolved by the telescope beam are elongated in a direction perpendic ular to the outflow axis. The clearest elongation is seen in the most collimated outflow, that of L1287. For this source, a remarkable veloc ity gradient can be seen along the major axis of the high-density cond ensation, consistent with a rotation of the core. For L1287 and AFGL 5 142 we find that the masses of the high-density cores are much higher than the masses of the outflows, indicating that the elongation of the cores cannot be a consequence of the interaction with the molecular o utflow and that the cores can play an important role in the large-scal e collimation of the bipolar molecular outflows. For all the cores the molecular gas is probably heated by an internal source. In particular , in L1287 we find a local heating of the molecular gas and line broad ening toward the position of the ammonia peak, indicating a physical a ssociation of the high-density gas with the powering source of the out flow.