Ratio of post-impact envelope mass to the NC envelope mass after the impact at t_comp (same core mass). All computed impactors and target sizes are shown. Top: abscissa shows the target core mass. Both large impactors provide sufficient energy to overcome the envelope binding energy for all targets. For the larger cores, runaway gas accretion is triggered. The smaller impacts do not have enough energy to significantly affect the large targets. Bottom: abscissa shows impact energy as fraction of the total binding energy. Left of the vertical dashed line, the impact shockwave is not capable of ejecting the envelope directly (assuming that 10% of the impact energy directly heats the envelope).