Parameter distributions of the binary population after the CE phase. These BH–He-star binaries include systems that are going to form BH–NS binaries and BBHs with GW inspiral timescales bigger than the Hubble time. We show the distributions of orbital separation A, first-born BH mass M_BH, He-star mass M_He-star and metallicity Z weighted by the integrated redshift- and metallicity-dependent SFR over the cosmic time (see Eq. (B.10)). The lighter shades represent larger contour levels, 68, 95 and 99%, respectively, constructed with pygtc (Bocquet & Carter 2016).