Progenitor masses of GW190425 at Milky Way-like metallicity in the default simulation. The colour indicates the time until the GW merger. The models are selected according to the reported binary mass of and chirp mass of , where errors mark the 90 per cent confidence interval (Abbott et al. 2020). The solid black line marks the binaries with equal primary and secondary mass. At the top, the primary masses are collapsed to a probability distribution.