HE-3 IN THE MILKY-WAY INTERSTELLAR-MEDIUM - SUMMARY OF RELEVANT OBSERVATIONS

We summarize spectral line and continuum observations of a sample of 2 1 Galactic H II regions made at 3.46 cm wavelength during the past 14 years as part of a program to measure the abundance of He-3 in the Mil ky Way interstellar medium. Converting the observed He-3(+) column den sity into an abundance ratio relative to hydrogen depends on the densi ty and ionization structure of each nebula. The observations needed to model our sources were made with the NRAO 140 foot (43 m), NRAO VLA, and MPIfR 100 m telescopes. Here we describe and compile our measureme nts of the He-3(+) emission line as well as those of various recombina tion transitions of H, He, and C. We also summarize the continuum data base which includes single-dish observations and interferometer maps.