Contribution of the various CO lines to the Poisson term (left panels) and the large-scale power spectrum (right panels) before (upper panels) and after (lower panels) masking the known galaxies from surveys. Together with the total CO (solid black line), we show the contribution of CO(2–1) (long-dashed red line), CO(3–2) (short-dashed orange line), CO(4–3) (dotted green line), CO(5–4) (long-dash-dot turquoise line), CO(6–5) (two-dot-dash light-blue line), CO(7–6) (dot-two-dash dark-blue line), and CO(8–7) (two-dash-two-dot purple line). For a better visualization, we smoothed the curves by a Gaussian kernel with a σ of 3 GHz.