Line ratio (a), (b), (c), and (d) distribution of the observed region. The overlaid contours are ¹³CO (3–2) integrated intensities, which start from 0.9 K km s⁻¹ (6σ) and increase by 0.9 K km s⁻¹. The beam sizes are shown in the lower left corner of panel a. In all panels, the (0, 0) offset corresponds to α_J2000 = 22^h18^m00^s.44, δ_J2000 = 61°49′03.′′7. In panels c and d, the cross represents the peak position of region C2 that is analyzed in Fig. 13.