Left: map of the Spitzer IRAC 3.6 μm (green) and 4.5 μm (red) coverage in the Spitzer Cosmic Dawn Survey around the NEP (Moneti et al., in prep.). Right: comparison between spectroscopic and photometric redshifts in our sample. Green circles are 541 ‘clean’ galaxies with spectroscopic redshifts in the HEROES field. Black dots are a sample of 263 AGN with spectroscopic redshifts in the field. The dashed and dotted lines refer to a redshift error of Δz/(1 + z) = ±0.15.