A survey of radio H II regions in the northern sky

Abstract

Nearly 500 radio continuum sources near the Galactic plane at declinations >~ -37^deg^ were examined for radio recombination line emission to see if they might be H II regions. A total of 462 were detected, about half of these for the first time. The data are presented in an extensive table. Among the newly discovered nebulae are several with recombination lines so narrow that their electron temperature must be < 4600 K. In one case the line width (in several transitions) is only 11.6 km s^-1^, requiring T_e_ <~ 2900 K.