Radial velocities of SNRs and H II regions within 20° in Galactic longitude of CTB 1 as a function of distance. The radial velocities of our three target SNRs are indicated. Information about the H II regions was taken from Brand & Blitz (1993). The radial velocities and distances of the SNRs were taken from Kothes et al. (2001) (G106.3+2.7), Kothes et al. (2002) (CTB 109), Goss et al. (1988) and Reed et al. (1995) (Cas A), Pineault et al. (1993) (CTA 1), Reynoso et al. (1999) and Chevalier et al. (1980) (Tycho), A. Yar‐Uyanıker et al. (2004, in preparation) (G126.2+1.6 and G127.2+0.5), Green & Gull (1982) and Wallace et al. (1994) (3C 58), and Routledge et al. (1991) (HB 3).