C¹⁸O rotational temperature (a), dust temperature (b), H₂ column density (c), C¹⁸O column density (d), C¹⁸O fractional abundance (e), velocity centroid (f), nonthermal velocity dispersion (g), magnitude of velocity gradient (h), and position angle of velocity gradient (i) plotted as a function of their distance to the crest of SE. In c, the yellow shaded region marks the star formation threshold of A_v = 7–10 mag (e.g., Johnstone et al. 2004; Lada et al. 2010; Heiderman et al. 2010; André et al. 2010; Könyves et al. 2015). In all panels, the radius of 0.1 pc is marked with a red dashed line, which indicates the transition discussed in Sect. 4.3. We note that the data points become incomplete at larger radial distances in panels a, d, e, and f due to the 3σ clipping mentioned in Sect. 3.4. In panel g, the two red horizontal dashed lines mark σ_t = c_s and σ_t = 2c_s where c_s is the soundspeed at a kinetic temperature of 7 K.