Image example showing one of the brightest clusters in our mock with the additional components we included in the simulation. A secondary halo is located in the south-east region compared to the brightest one. The events generated by clusters (AGN, the X-ray background) are displayed as small dots in blue (orange, green). The true halo position is shown with large crosses, colour-coded by the X-ray flux. The position of the X-ray wavelet (optical FoF) detection is located at the cyan circle (magenta triangle). Each galaxy is marked by the small plus signs, according to their g-r colour. The vertical colour bar refers to input groups and clusters (the large crosses), the bottom one to individual galaxies (small plus signs).