Contribution from ionised gas phase to [C II]. Shown are the median values of the different redshifts (solid lines) and their 25th and 75th percentiles (dotted lines), and the observational data and the respective fit made by Cormier et al. (2019, black dashed line). The grey dots are the data from Croxall et al. (2017), while the red dots are from Cormier et al. (2019) at z = 0. Left panel: predictions of REF-L100N1504; Right panel: predictions of RECAL-L0025N0752. Only the bins with more than 5% of the total sample of galaxies for the respective simulation are shown.