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Astron. Astrophys. 345, L43-L46 (1999)

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Letter to the Editor

A double system of ionized jets in IRAS 20126+4104

P. Hofner 1,2, R. Cesaroni 3, L.F. Rodríguez 4 and J. Martí 5

1 Physics Department, University of Puerto Rico at Rio Piedras, P.O. Box 23343, San Juan, Puerto Rico 00931
2 Arecibo Observatory, NAIC/Cornell University, HC3 Box 53995, Arecibo, Puerto Rico 00612
3 Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Florence, Italy
4 Instituto de Astronomia, UNAM, Apdo. Postal 70-264, 04510 México D.F., México
5 Departamento de Física, Escuela Politécnica Superior, Universidad de Jaén, Calle Virgen de la Cabeza, 2, E-23071 Jaén, Spain

Received 2 March 1999 / Accepted 6 April 1999


We have imaged the [FORMULA]mm and [FORMULA]cm continuum emission from the high mass (proto)star system IRAS 20126+4104 with the VLA. The [FORMULA]mm emission appears unresolved with a synthesized beam of [FORMULA], and comparison with [FORMULA]mm and [FORMULA]mm fluxes indicates a spectral index of about 3, so that emission from dust with an absorption coefficient proportional to [FORMULA] is suggested.

The [FORMULA]cm emission consists of two elongated structures of approximate size [FORMULA], 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 [FORMULA]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 CH3CN emission which is oriented perpendicular to the [FORMULA]cm continuum emission. In this case the measured fluxes are consistent with ionization caused by either shocks or stellar UV photons.

Key words: stars: formation – ISM: H ii regions – ISM: jets and outflows

Send offprint requests to: hofner@naic.edu

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© European Southern Observatory (ESO) 1999

Online publication: April 28, 1999