Recombination Lines near 8·9 GHz of Strong Sources in the Southern Milky Way

Abstract

Seventeen intense nebulae in the southern Milky Way have been surveyed for their radio recombination lines of hydrogen and helium, H 90IX, He 9OIX, H 113ft, H 129y, and of elements heavier than helium, X901X. The H901X line for 30Doradus in the Large Magellanic Cloud was also observed. Data on source size, flux density, continuum temperature, line temperature, line half-width and radial velocity are used to derive information about the sources. This information includes electron temperatures and turbulent velocities, the abundance ratio of singly ionized helium to ionized hydrogen, and the intensity ratios of ft and y lines to IX lines. The lines from elements heavier than helium are discussed.