Simulation time when the impacts occurred for all gap-causing flybys summed over all 50 simulations. Each perturbing cluster is labeled and color-consistent. We report the time axis in simulation units, with 1 s kpc km ⁻¹ corresponding to roughly 1 Gyr. We note that the plot breaks the y-axis to accommodate the large number of encounters from NGC 2808 without overshadowing the other interactions.