Depiction of the initial condition of the M = 1.05M_E multi-layered PES model. Here, we show how the true density compares with the approximated density from the SPH summation formula. The initial SPH density is given from the initial distribution of particles using the method described in Appendix B. The density after relaxation is given by the green curve. We can see that in general we get a very good fit; however, we do get a slight a gap between the density discontinuities, which is characteristic of the artificial surface tension effect (Agertz et al. 2007).