Filament skeletons based on TM results. The skeletons correspond to a scale of F₁ = 0.6′ and the TMN method except for the thick black line that shows the only skeleton found at the scale of F₁ = 5.0′ and without data normalisation. The background is the Herschel 250 μm surface brightness image in units of MJy sr^-1. The lower frame shows details of a smaller region (marked with a box in the upper frame) where the F₁ = 0.6′ skeletons are drawn in black for better contrast.