Detection of 7 Millimeter Sources near Cometary H [CSC]ii[/CSC] Regions

Abstract

We present 7 mm VLA observations of five ultracompact H II regions of cometary morphology that have H2O masers near their cometary arcs. We detect 7 mm sources near two of these, NGC 6334F and G75.78+0.34. In the latter case, the emission coincides with the cluster of H2O masers. We discuss the possibility that the observed 7 mm emission could be produced by warm dust condensations or optically thick ultracompact H II regions. Additional studies are required to establish firmly the nature of the emitting sources that may be tracing the very early stages of massive star formation. The presence of such young objects near the head of cometary ultracompact H II regions may favor, in these cases, either the champagne model or a mass-loading model as explanations for the radio continuum morphology.