Example of fitted molecular spectra for V_LSR detection for the Hi-GAL source HIGALBM340.2690-0.0542. The spectra are (a) NANTEN ¹²CO(1–0), (b) MOPRA ¹²CO(1–0), (c) TRUMMS ¹²CO(1–0), (d) SEDIGISM ¹³CO(2–1), (e) SEDIGISM C¹⁸O(2–1), (f) MALT90 HCO⁺. In all panels the black, red, and green curves are the extracted profile, the fitted lines, and the residual, respectively. The background gray area is the ±σ_noise value where σ_noise is the root mean squared value of the noise amplitude (see Appendix A). The horizontal blue line shows the 5σ level.