Time evolution of the circumgalactic medium of the simulated galaxy group, showing the central region at three successive moments close to the merger event. The two columns display maps of the X-ray surface brightness and the projected energy density of cosmic ray electrons, while the two panels in each column represent two orthogonal sight lines. For the X-ray map, we assume a distance of z = 0.017. The scale bar (the top left panel) indicates 200 kpc. The time labels provide the elapsed time since shortly before the merger event.