Visualisation of the fitting formula for the remnant mass in Foucart et al. (2018), showing the dependence on the BH spin (χ_BH), mass ratio (Q), and NS tidal deformability (Λ_NS). Best-fit values for the free parameters are assumed. In each of the three panels, χ_BH, Q,  or Λ_NS is kept constant, as shown in the title of the panel, and the other two parameters are varied. The coloured regions indicate the amount of remnant mass (M_rem) in solar masses.