Upper panel: H₂ column density of TMC-1 NH₃ derived fromHerschel and Planck data (Rodríguez-Baras et al. 2021). The triangles mark the positions observed with the GEMS large project. Lower panel: CH₃OH and C¹⁸O column densities, and column density ratios computed in the different offsets in TMC-1 NH₃ in the two velocity components observed for methanol. In the plot of the CH₃OH and C¹⁸O column density ratio, the A_V in each offset is marked in red.