Synthetic CO spectral lines for three selected models. From left to right these are v05a09, v10a25, and v20a25 with the J =2→1, 4→3, 6→5 transitions, respectively. The spectral lines are created viewing face-on (upper row) and edge-on (lower row). The black dashed lines show the original spectral line, and the red line has the addition of white noise assuming a S/N of 10, and an increased velocity bin size to 500 m s⁻¹.