X_CI × α_CO, X_CI × α_[CII], and X_CI × δ_GDR (left column) and α_CO/α_[CII], δ_GDR/α_CO, and δ_GDR/α_[CII] (right column) as a function of L_IR for our sample. Our sample is represented in squares, colour-coded by the CO transition used to estimate the CO-based gas mass: CO(1–0) transition in purple, CO(2–1) in blue, CO(3–2) in red, and CO(4–3) in brown (top and centre rows). We also compare our sample with the sample presented in Dunne et al. (2021) (black circles), SMGs (black stars), main-sequence galaxies at z ∼ 1 (black diamonds), and AGNs (grey diamonds) from the Valentino et al. (2020) compilation. The mean and the median y values are shown as green solid and dashed lines, respectively, in the left panel. The green shaded region represents the 1σ region around the sample mean.