TMC-1N column density map and filament profile derived from WFCAM extinction map. a) Column density map. The part of filament used in the fitting is marked with white line (based on the Herschel column density map in Fig. 3). b) Average column density profile of the filament (black line), fitted Plummer profile (red dashed line) and the baseline of the fit (blue dashed line). Values for fitted Plummer parameters ρ_c, R_flat, and p are marked in the figure. c) FWHM values (black circles and left hand scale) and column density along the ridge of the filament (solid line and the right hand scale).