New Distances to Four Supernova Remnants

Distances are found for four supernova remnants without previous distance measurements. H I spectra and H I channel maps are used to determine the maximum velocity of H I absorption for the four supernova remnants (SNRs). We examined ${}^{13}$CO emission spectra and channel maps to look for possible molecular gas associated with each SNR, but did not find any. The resulting distances for the SNRs are $3.5\pm 0.2$ kpc (G24.7+0.6), $4.7\pm 0.3$ kpc (G29.6+0.1), $4.1\pm 0.5$ kpc (G41.5+0.4) and $4.5\pm 0.4-9.0\pm 0.4$ kpc (G57.2+0.8).