Distribution of the physical properties derived from H₂CO (1_1,0–1_1,1). (a) Distribution of the peak optical depth of the H₂CO (1_1,0–1_1,1) line. The HPBW of the H₂CO image is 3′. The color bar represents the peak optical depth. The HII regions from Anderson et al. (2014) are marked with solid red circles, and SNR G78.2+2.1 is indicated by the dashed orange circle. The blue crosses represent the radio continuum sources and active star-forming objects, and the purple star represents the massive star cluster, Cygnus OB2. (b) Similar to Fig. 6a, but the HPBW of the H₂CO (1_1,0–1_1,1) image is 10′.8. (c) Similar to Fig. 6b, but for the H₂CO column density at the 1_1,0 level. In all panels, the beam size is shown in the lower left corner.