Galactic supernova remnants: dependence of radio brightness on galactic height and its implications

Abstract

The variation of radio brightness across individual shell supernova remnants has been investigated; on the average, the brightness decreases with increasing distance from the galactic plane (z), with a scale height of 110 pc. Part of the brightness gradient results from a dependence of diameter (D) on the density of the interstellar medium, but much of the gradient represents a z-dependence intrinsic to the radio emission process.