Interaction between a Massive Molecular Outflow and Dense Gas Associated with IRAS 22142+5206

Abstract

We report results of 12CO, 13CO, and C18O (J = 1–0) observations made toward the luminous protostellar candidate IRAS 22142+5206 (~16,100 L⊙, at its kinematic distance of 4.5 kpc) using the 45 m telescope at Nobeyama Radio Observatory. We have discovered a massive CO outflow with a molecular mass of ~33 M⊙, which is among the more massive outflows reported to date. The outflow lobes extend to over ~2 pc from the IRAS source. Dense gas (~1140 M⊙) with an elliptical shape is also found around the source, with a velocity gradient of ~0.5 km s-1 pc-1 along its major axis. We find a cavity in the dense gas at positions where the CO outflow is prominent. We discuss the origin of the cavity, estimating the mechanical momentum and kinetic energy of the outflow, and conclude that the cavity was most likely created by the high-velocity jet of the outflow, which may have swept up part of the dense gas. We also carried out extensive 13CO observations toward the IRAS source using the Nagoya 4 m telescope in order to reveal the overall distribution of molecular gas around the source. The results of these observations indicate that the IRAS source is embedded in a molecular cloud with a mass of 7300 M⊙.