Example mergers from TNG at different merger stages (obtained from the corresponding merger trees in the simulation): pre-mergers (−0.8 < dt < −0.1 Gyr), ongoing-mergers (−0.1 < dt < 0.1 Gyr), and post-mergers (0.1 < dt < 0.3 Gyr). Each row shows a galaxy along its merger sequence. Images have an approximate physical size of 160 kpc, displayed using an arcsinh inverted grey scale.