VLA observations of massive star formation in spiral nuclei

Abstract

Both the spectral and spatial information in high-resolution radiocontinuum maps is used to decouple thermal emission due to H II regionsfrom the extended, strong synchrotron emission found in galactic cores.A first-order analysis, assuming constant spectral indices across themaps, yields thermal fluxes to within a factor of 2. The presence oflarge numbers of H II regions and young stars in the nuclear regions ofthree nearby spiral galaxies is thus confirmed.