Ultracompact H II regions with extended radio-continuum emission

We have conducted a 3.6 cm radio-continuum survey with the VLA in its compa ct D-array to look for extended radio-continuum emission around known ultra compact H II regions. We find extended emission in 12 out of 15 fields. The extended emission ranges in size up to 5', with typical diameters of 60 ", or 2 pc. In some cases, the extended component produces an order of magnit ude more flux than the ultracompact component. It is possible that the exte nded emission is from H II regions not connected with the ultracompact H II regions, but on the basis of the morphology of the emission, we believe th at it is possible or even likely that the ultracompact and extended emissio n are directly connected in about half of the sources. The possible consequ ences of directly connected extended emission are profound. We may be force d to reconsider the definition of an ultracompact H rr region and consider models in which dense, ultracompact ionized components are embedded in less dense, more extended regions.