H₂ Column density map (a) and dust temperature map (b) derived using PPMAP. The black contours on (a) and the orange contours on (b) show H₂ column density contours at 400, 800 and 1600 × 10²⁰ cm⁻². In axes figure shows the three spines traced by Hessian methods as solid black lines. Green-dashed lines show the perpendicular cuts along the ridge offset from the spine centre by 0.63 pc. Theses are used for further analysis. Labeled arrows point toward the active and quiescent parts of the filament and labeled magenta crosses show the location of three bubbles, S109, S110, and S111, cataloged in Churchwell et al. (2006). The white solid line indicates a physical scale of 5 pc.