Distances of Galactic Supernova Remnants Using Red Clump Stars

We carry out a project to independently measure the distances of supernova remnants (SNRs) in the first quadrant of the Galaxy. In this project, red clump (RC) stars are used as standard candles and extinction probes to build the optical extinction (A _V )-distance(D) relation in each direction of extinction-known SNRs. The distances of 15 SNRs are determined. Among them, the distances of G65.8-0.5, G66.0-0.0, and G67.6+0.9 are given for the first time. We also obtain 32 upper/lower limits of distances, and the distances to G5.7-0.1, G15.1-1.6, G28.8+1.5, and G78.2+2.1 are constrained. Most of the distances measured by the RC method are consistent with previous results. The RC method provides independent access to the distances of SNRs.