Distance measurements to radio supernova remnants

Abstract

We briefly review methods to measure the distances to Galactic radio supernova remnants (SNRs) and objects associated (pulsars and HII regions). We highlight new methods we have developed by giving results from HI and 13CO line spectra of some SNRs. The methods advance traditional methods of HI-absorption-determined-distance to an SNR due to improving background subtraction and spurious emission rejection, and resolving the near/far distance ambiguity in the inner Galaxy. New distances to several SNRs, i.e. W41, G21.5∓0.9, G54.1+0.3, Kes 67, Kes 69, Kes 73 and Kes 75, have been determined.