Position-velocity diagram of CO, NH\(_{3}\), and \(\rm{N}_{2}\rm{H}+\) emission for filament 9. Blue background shows \(^{12}\)CO (1-0) emission integrated between \(-1^\circ < \textrm{b} < 1^\circ\) \citep{Dame_2001}. Black dots show HOPS and MALT90 sources associated with filament 9. Colored lines are fits to the Scutum-Centaurus arm (see text for references).