A double system of ionized jets in IRAS 20126+4104
Abstract
We have imaged the 7 mm and 3.6 cm continuum emission from the high mass (proto)star system IRAS 20126+4104 with the VLA. The 7 mm emission appears unresolved with a synthesized beam of 1.7" x 1.0", and comparison with 3 mm and 1.3 mm fluxes indicates a spectral index of about 3, so that emission from dust with an absorption coefficient proportional to nu is suggested. The 3.6 cm 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 3.6 cm 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 CH_3CN emission which is oriented perpendicular to the 3.6 cm continuum emission. In this case the measured fluxes are consistent with ionization caused by either shocks or stellar UV photons.
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- May 1999
- Bibcode:
- 1999A&A...345L..43H
- Keywords:
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- STARS: FORMATION;
- ISM: H II REGIONS;
- ISM: JETS AND OUTFLOWS