Number of fragments that hit Earth, N_imp, as a function of t_imp − t_int for a set of impact models (assuming longitude of δ = 0° , 90° , 180° and 270°, see model details in Table 1). Left and right panels show asteroid-type (models A1-A4) and comet-type (models C1-C4) impactors, respectively. Models assume four cloud expansion velocities, v₀ indicated with four distinct colours. The warm and cool colours represent the asteroid-type (v_imp = 20 km s⁻¹) and comet-type (v_imp = 40 km s⁻¹) impactors. The gravitationally interacting models are shown with symbols. The non-interacting impact cloud models are shown with thin solid and thin dashed lines, respectively. Thick solid lines represent the theoretical impact number given by equation D.1, for which case the effect of orbital dynamics on the cloud and the fragment’s self-gravity are neglected.