CN N = 3 − 2 (top) and N = 2 − 1 (bottom) emission measured with the ACA data presented in this article. Panels are centered at 340.248 and 226.874 GHz, which is the frequency of the stronger emission hyperfine transition. The data are fitted with three simple models. Left: single component corresponding to the fit presented in Sect. 4.3.2, where a source size θ_s = 5″ is assumed. The central opacity of the brightest transitions are τ_3 − 2 = 0.25 and τ_2 − 1 = 0.44, while the cumulative opacity of the stronger hyperfine groups are and . See text in Sect. 5.5 for details. Center: single component fit assuming a smaller source size of θ_s = 2.5″. Physical parameters of the fit are log(N) = 16.43 cm⁻², T = 13.4 K, v_lsr = 229 km s⁻¹, δv_1/2 = 118 km s⁻¹. Opacity of brighter transitions are τ_3 − 2 = 1.6 and τ_2 − 1 = 2.1, and group opacities and . Right: two component model assuming two sources of sizes θ_s = 5″/1.5″. Physical parameters of models are log(N) = 15.6/17.3 cm⁻², T = 10.2/10.0 K, v_lsr = 232/220 km s⁻¹, δv_1/2 = 150/76 km s⁻¹. Opacity of brighter transitions are τ_3 − 2 = 0.18 and τ_2 − 1 = 0.31 for the first component, while the thick component is completely saturated. Blue and green lines represent the two components, respectively, with sum of both models is represented by the red line.