Spatial distribution of the OH⁺ 1₂–0₁ emission, integrated between V_LSR = +6 and +10 km s^-1 (top), between +8 and +12 km s^-1 (middle), and between +10 and +14 km s^-1 (bottom). Greyscale levels start at 0.6 K km s^-1 and increase by 0.2 K km s^-1. Contours of CO 10–9 emission are at 5, 15, ... 95% of the peak intensity in the respective velocity channel. Vibrationally excited H₂ peaks near the north-west edge of the CO emission (cf. Fig. 1 of Nagy et al. 2013).