A multiwavelength picture of the AFGL5142 star-forming region.

by

T.R. Hunter 1, L. Testi 2, G.B. Taylor 1, G. Tofani 3, M. Felli 3, and T.G. Phillips 1

1 California Institute of Technology, Departement of Physics, Math and Astronomy, 320-47, Pasadena, CA 91125, U.S.A.

2 Dipartimento di Astronomia e Scienza dello Spazio, Universitá di Firenze, Largo E. Fermi, 5, I-50125 Firenze, Italy

3 Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze, Italy

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 about 2 arcmin on each side of the center. In the perpendicular direction, we find consistent evidence for a second, more compact (<0.5 arcmin) 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 (UC) radio continuum source (most probably an ionized stellar wind). The {H2O} cluster is composed of five spatial components: two are within 0.2-0.3 arcsec from the YSO (a few hundred AU) and three are at larger distance (1.5-2 arcsec, 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 4 10^3 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.


Mantained by: Leonardo Testi

lt@arcetri.astro.it