Age density maps as a function of the R_birth for the in situ stellar particles that comprise the stellar halo at z = 0. The arrows represent the time at which the galaxies underwent merger events. Only merger events that satisfy that the maximum total mass reached by the satellite was $\frac{1}{100}$ times the M₂₀₀ of the main galaxy are shown, and they are colour-coded according to their reached maximum total mass. The galaxies are plotted in order of decreasing stellar mass. The vertical dashed lines indicate 4 R_h.