A Multiwavelength Picture of the AFGL 5142 Star-forming Region

Abstract

We present molecular line, H2O maser, radio continuum and near infrared maps of the bipolar outflow source AFGL5142. The high resolution of our molecular CO observations enables us to define the morphology of the large-scale bipolar outflow into a two lobe structure extending for 2' on each side of the center. In the perpendicular direction, we find consistent evidence for a second, more compact (<0.5') outflow in the form of a spatial velocity offset in the CO map and of an H2 jet-like structure derived from a near infrared narrow band image. On a smaller scale size, the radio and infrared continuum observations reveal the engines of the molecular outflows. The maser emission occurs near the position of the most embedded source of the cluster, IRS1. This is located at the center of the compact outflow and jets of shocked H2 and coincides with an ultra compact radio continuum source (most probably an ionized stellar wind). The H2O cluster is composed of five spatial components: two are within 0.3'' from the YSO (a few hundred AU) and three are at larger distance (1.5--2'', a few thousand AU). A marginal detection of proper motion of the two more distant masers may suggest a high expansion velocity at a distance 4000 AU from the YSO, similar to what is found in Orion KL and W49N. The brightest NIR source of the cluster (IRS2) is associated with an IRAS point source and lies along the axis of the large-scale bipolar outflow. We propose that the masers and the compact molecular outflow are powered concurrently by the wind from the YSO associated with IRS1, while the large-scale outflow could be the remnant from the formation of IRS2.