Gas-to-dust ratio and CO emission. Left: gas-to-dust ratio as a function of metallicity for the galactic CO to molecular gas conversion from Rémy-Ruyer et al. (2014, RR14). The dashed line represents the reference scaling of the δ_GDR with metallicity and the dotted and dash-dotted lines represent the best power-law and best broken power-law fits to the data presented in RR14. The dashed blue line with the shaded envelope show the δ_GDR – metallicity relation from Magdis et al. (2012) which we used to derive the original M_gas. The δ_GDR measurement from CO and dust continuum is shown as a red diamond. Right: CO(2−1) line luminosity to M_dust ratio and δ_GDR as a function of M_dust. For the δ_GDR, we assume α_CO = 4.0 for all galaxies. We also show the sample of MS (blue) and SB (purple) galaxies from Valentino et al. (2020). The BzK galaxies from Daddi et al. (2015) are shown as black squares. Our galaxy is shown as a red diamond. A typical uncertainty on the data is shown in the bottom left corner.