Longitude–velocity diagram for the BGPS. Background image is the latitude-integrated ¹²CO intensity of Dame et al. (2001). Black circles mark the locations of BGPS V2 sources, and magenta squares identify the H II regions from Table 2. Yellow stars mark the trigonometric parallax measurements presented in Table 1 of Reid et al. (2014). The kinematic avoidance zones discussed in Section 3.2.2 are shown as hashed regions. Various Galactic features are identified.