Comparison of the evolution of the orbital separation of the various AREPO runs with the simplified drag model (left panel a), and the dynamic response number R_d and the local ratios of inspiral and convective turn-over time (right panel b). The evolution of the orbital separation of a 0.08 M_⊙ companion is similar to that of the 0.05 M_⊙ companion (Fig. 7) and therefore not shown here for clarity.