1999A&A...345L..43H

We have imaged the 7mm and 3.6cm continuum emission from the high mass (proto)star system IRAS 20126+4104 with the VLA. The 7mm emission appears unresolved with a synthesized beam of 1.7"x1.0", and comparison with 3mm and 1.3mm fluxes indicates a spectral index of about 3, so that emission from dust with an absorption coefficient proportional to ν is suggested. The 3.6cm emission consists of two elongated structures of approximate size 0.8"x≤0.2", the northern source being coincident with the millimeter emission. The position angle of both sources is identical to the large scale molecular outflow seen in HCO⁺(1-0). We discuss explanations for the origin of the 3.6cm continuum emission and although a cluster of three ultracompact HII regions provides a feasible model, we favor the interpretation of thermal ionized jets, based on the morphology of the emission, the velocity distribution of water masers coincident with the northern source, and the CH₃CN emission which is oriented perpendicular to the 3.6cm continuum emission. In this case the measured fluxes are consistent with ionization caused by either shocks or stellar UV photons.