The BBH delay time distributions from our fiducial model for binaries formed at redshifts 0.2, 2, and 6. (Left) The distributions normalized to an area of one. The bin widths are log-uniformly and uniformly spaced in the left and right panels, respectively. (Right) The three gray hatched regions are the portion of each distribution that would not merge by z = 0. The lowest t _delay bins (those with t _delay ≲ 10 Myr) suffer from sampling uncertainty.