Example of merger ICs prepared with DICE (see Sect. 2.1.4). The density map in the X − Y plane shows the total (dark matter+stars) density (ρ) that has been mass-averaged along the Z axis. The two progenitors were placed in the simulation box at a distance of D = 8 kpc along the X axis and with an impact parameter of |Y₁|+|Y₂| (Eq. (5b)). The arrows mark the direction of the initial velocity of each progenitor (Eq. (5c)).