Upper panel: methanol and C¹⁸O column density ratio for two cores in the north of B213, C1 and C5. Lower panel: methanol and C¹⁸O column density ratio for two cores in the south of B213, C10 and C16. The column density ratios are plotted with respect to the observed offsets, and offset 1 always refers to the dust peak (also shown as a dashed green line). The positions of the offsets in the cores are shown in Figs. A.15, A.17, A.20, and A.22.