Comparison of the retrieved α_CO conversion factor to the SFR for each individual snapshot of the SB merger model (top – averaged over three projections for each snapshot). A clear correlation is found between SFR and α_CO within the SB merger galaxy type, and the intrinsic variations in the SFR in the SB merger model induce a larger scatter in α_CO than for isolated disk models. This indicates that stronger starbursts could have even lower α_CO factors, given that the merger model used here is moderately starbursting about at the LIRG/ULIRG transition regime. In contrast, other galaxy types do not follow this α_CO–SFR trend retrieved for the SB merger snapshots (bottom). In particular, high-z disks have an SFR that is almost as high as some SB merger snapshots, but with much higher α_CO (see also Fig. 11).