Top: APEX CO and [C I] spectra in the northern map, averaged over the filament crest (N > 3 × 10²¹cm⁻²). Bottom: APEX CO spectra averaged over the southern map and the 7-pixel averaged SOFIA [C II] and [O I] lines that are not detected above the 3σ level. We note the prominent blueshifted velocity component around 2.8 km s⁻¹ in the north and at 2.5 km s⁻¹ in the south, only visible in the ¹²CO lines.