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

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1. Introduction

Energetic outflow phenomena such as bipolar molecular flows, Herbig-Haro objects, and emission from shocked H2 are commonly observed in regions of star formation. Many of these phenomena can be explained by a scenario involving an accretion disk/jet system. For low mass systems there are several excellent observational examples (e.g. Rodríguez et al. 1999, Torrelles et al. 1997) for disk/jet systems, where the disk can be traced by emission from the dust continuum at mm wavelengths, and the jets through their continuum emission at cm wavelengths, which in most cases is thermal emission from ionized gas in the jet. However, for regions where OB type stars are being formed, our knowledge of how the high velocity gas observed in these regions is collimated and driven remains scarce.

In this paper we present observations of the high-mass (proto)star IRAS 20126+4104 (hereafter I20126). This system shows a large bipolar molecular flow and, on a much smaller scale, an elongated structure perpendicular to the flow, interpreted as an accretion disk around the central object (Cesaroni et al. 1997, 1999; Zhang et al. 1998). Previous observations at cm wavelengths have only resulted in upper limits with the exception of the [FORMULA]cm observations of Kurtz et al. 1999who measured a flux density of [FORMULA]mJy and an upper limit to the size of [FORMULA]. We have used the NRAO's Very Large Array (VLA) 1 to observe I20126 in the [FORMULA]mm and [FORMULA]cm continuum bands. The results of these observations are presented below. Throughout the paper we assume a distance to I20126 of [FORMULA]kpc (see Cesaroni et al. 1997).

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© European Southern Observatory (ESO) 1999

Online publication: April 28, 1999
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