Deconvolved size of the 50% contour level of the integrated emission of the different transitions shown in Figs. 8−10 versus upper level excitation energy. Black circles correspond to CH₃CN and CH₃CN v₈ = 1 transitions. The black open circle corresponds to the K = 2 transition of the isotopologue of CH₃CN, that is, CHCN. The black arrow indicates an upper limit for the deconvolved size because the emission in unresolved. The red triangles correspond to the other species shown in Figs. 9 and 10. The typical error bar of the size measurements is shown in the bottom left.