Comparison between CO luminosity from the SIDES simulations (solid black lines) and the observations for various transitions and redshifts (see details above each panel). Observational data are represented by filled rectangles, whose width indicates the bin size and whose height shows the 1-σ confidence region. The PdBI HDFM program of Walter et al. (2016, 1 arcmin²) is in green. The ALMA/ASPECS pilot program is in blue (1 arcmin² Decarli et al. 2016) and the large program is in red (4.6 arcmin²Decarli et al. 2019, 2020).