A 5 GHZ VLA SURVEY OF THE GALACTIC PLANE

We have used the VLA to survey the inner Galaxy (Absolute value of b < 0.4-degrees, l = 350-degrees-40-degrees) at 5 GHz to a limiting sensitivity of between 2.5 and 10 mJy. The survey has resulted in a catalog of 1272 discrete sources (including 100 sources outside the formal survey area) of which we have tentatively identified approximately 450 as ultracompact H II regions and approximately 45 as planetary nebulae. Approximately 30% of the radio sources are detected in the IRAS Point source Catalog. The results confirm a scale height of only 30 pc for ultracompact H ii regions. We show that source lists generated from the IRAS Point Source Catalog alone suffer serious selection effects; the combination of the IRAS and radio surveys allows us to produce a much more complete census of the regions of massive star formation in our Galaxy.