Dense gas and exciting sources of the molecular outflow in the AFGL 437 star-forming region

Abstract

We present Very Large Array (VLA) high-resolution observations of the NH 3(1,1) and NH 3(2,2) molecular transitions towards the high-mass star-forming region AFGL 437. Our aim was to investigate if the poorly collimated CO molecular outflow previously detected in the region is the result of a projection effect, with no intrinsic bipolarity, as suggested by Gómez et al. We complemented our observations with radio continuum archived data from the VLA at 2 and 3.6cm, and with unpublished public data at 450m taken with Submillimetre Common-User Bolometer Array at the James Clerk Maxwell Telescope. Ammonia emission was found mainly in three clumps located at the south and east of the position of the compact infrared cluster of AFGL 437, where the CO outflow seemed to have its origin. One of the NH 3(1,1) clumps coincides with the maximum of NH 3(2,2) and with a local peak of emission at 450m. A near-infrared source (s11) is also found at that position. Our continuum map at 2cm shows extended elongated emission associated with the infrared source AFGL 437W. This elongated morphology and its spectral index between 3.6 and 2cm (∼0.4) suggest the presence of a jet in AFGL 437W. We suggest that several molecular bipolar outflows may exist in the region. The observed CO outflow would be the superposition of those individual outflows, which would explain its low degree of collimation observed at larger scales. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.