Enclosed mass and energy conservation as a function of time. We show the same simulations as in Fig. 12 (O, P, R, and S in Table A.1). The upper panel gives the mass within a radius of 0.15 kpc and the lower panels shows how well the total energy is conserved. The time for the simulations with a velocity-independent cross-section is rescaled to match the collapse phase of the simulations with velocity-dependent interactions.