Examples for structures derived with different methods, coordinates are identical with Fig. 2. Left: filaments derived for 857 GHz FIR data in Paper II, shown are eigenvalues −50 < λ_ < −1.5 K/deg⁻². Center: PPV_fil with color coding in velocity, representing the corresponding velocity field in the range −30 < v_LSR < 30 km s⁻¹. Right: caustics in H I column density maps from Paper II, integrated from −50 < v_LSR < 50 km s⁻¹ with eigenvalues −250 < λ_ < −5 K/deg⁻².