Upper panel: excitation temperature defining the populations of N = 1 and 3 levels. Lower panel: total column density of C₂H. The asterisk represents Her 36, which is the central position (Δα = 0, Δδ = 0) at RA (J2000) = 18^h03^m40.3^s and Dec (J2000) = –24°22′43′′. The contour levels are 10–100% in steps of 10% of the corresponding peak emissions. The values of main beam brightness temperatures and that of the velocity integrated intensities for the N = 1 and 3 levels used to calculate the T_ex(C₂H) and N(C₂H) were extracted from maps convolved to the same resolution of 30′′.