SPECTRUM OF GALACTIC NONTHERMAL BACKGROUND-RADIATION .1. OBSERVATIONS AT 151.5 AND 408 MHZ

Observations of the galactic radio background radiation have been carried out at 15 I · 5 and 408 MHz with dipole arrays having a beamwidth of 17 ° x I 2 °, geometrically scaled from those used at 17·5 and 81·5 MHz by Bridle for similar measurements. The results indicate that between 17·5 and 408 MHz the galactic spectral index is frequency dependent and its value changes over the sky, the spectrum becoming steeper toward the region of minimum sky brightness and flatter toward the local spiral arm. Evidence for the existence of two or more components of the galactic radio-emission is suggested. © Royal Astronomical Society.