The four H₂Cl⁺ lines (black) used in the LTE model fitting with CASSIS, and the best-fit model (red). All spectra are corrected for the foreground PDR velocity of 9.4 km s^-1. The dashed red lines show the hyperfine components of H₂Cl⁺ transitions, while dashed blue lines in the top right panel indicate the native frequencies of C₂H transitions. The other H₂Cl⁺ transitions do not have any lines nearby that were listed as detections in the spectral survey of Kama et al. (2013).