BBH merger rate as a function of redshift compared to toy model merger rates assuming a scaled SFRD (left), a scaled SFRD with constant delay times (middle), and a scaled SFRD with a t ⁻¹ delay time distribution (right). All simulations are normalized to the same intrinsic merger rate R _merge,0. We assumed minimum delay times for the middle and right panel of 20 Myr. Labels and colors are the same as in Figure 1.