Interaction between the Outflow and the Core in IRAM 04191+1522

We have carried out mapping observations of the molecular core associatedwith the young Class 0 protostar, IRAM 04191+1522, in the CH3OH (JK=2K-1K) andC34S (J=2-1) lines using the 45 m telescope at Nobeyama Radio Observatory. Aswell as an elongated envelope associated with the protostellar formation (size\~0.07 pc x 0.04 pc, mass ~ 2.3 Mo), two compact (~ 0.03 pc) condensations werefound in the CH3OH line at the southern edge of the elongated envelope, wherethe blueshifted CO outflow emerging from the protostar is located. In contrastto the elongated envelope, those compact CH3OH condensations show much largerline width (up to 2.0 km s-1) with centroid velocities blueshifted by ~ 0.8 kms-1. The compact condensations have momenta (~ 0.06 Mo km s-1) comparable tothat of the blueshifted molecular outflow. These results suggest that thecompact condensations are probably formed in the course of interaction betweenthe outflow and the ambient gas surrounding the protostar, and that suchinteraction may cause dissipation of a part of the ambient gas. No drastic,localized enhancement of the CH3OH abundance is, however, observed toward thecompact condensations, implying that there seems to be no significant shockheating at the compact condensations. This may be because the CO outflowvelocity (< 10 km s-1) is too low to cause effective heating to release CH3OHon dust grains into gas phase.Comment: 22 pages, 7 gif figures, uses aastex.cl