Overlap of debris from different mergers in the L_z − E plane. Each pixel is coloured by the number of merger events contributing to that region, as given in the colour bar. Top row: Debris from all mergers for each HESTIA galaxy, as indicated above each panel. The largest overlap of mergers are shown in maroon. Bottom row: Same as top row, but limited to the five most significant mergers. These maps suggest that the most crowded region of the L_z − E space corresponds to the non-rotating region, which is where the Gaia-Enceladus merger was identified (Helmi et al. 2018). The number of merger remnants decreases in the regions of substantial rotation.