Energy spectrum of the simulated cosmic X-ray background components. The thick black dashed and plain lines are obtained with our model for AGN sources by stacking individual spectra of faint sources below f_lim = 10⁻¹⁴ (plain) or 3 × 10⁻¹⁵ (dashed erg s⁻¹ cm⁻². For comparison, the dot-dashed green line shows the model of Lumb et al. (2002) derived from XMM-Newton observations. Our emission model for the Galaxy (red and dotted lines) is described in the text.