A Study of Galactic Supernova Remnants, Based on Molonglo–Parkes Observational Data

Abstract

Observations with the Molonglo and Parkes radio telescopes have recently produced improved radio frequency data for the southern galactic supernova remnants (SNRs). We have now used these observations to investigate the general evolutionary properties of SNRs—the first such large-scale analysis based on a near-homogeneous data set. Empirical relationships are derived which describe in general terms the expansion of SNRs, at least during the adiabatic phase of their evolution. An improved SNR distance scale is established, based largely on Parkes H I absorption measurements, and the resulting relationship between surface brightness and linear diameter for galactic SNRs is found to be compatible with that determined for the Magellanic Cloud SNRs, contrary to earlier conclusions.