Comparison of simulated uncontaminated (left) and point-source contaminated (right) clusters. Top panel: surface brightness (SB) distribution showing the extracted cluster profiles (black crosses) are plotted against the blue line corresponding to the fitted β-model; the green line displays the particle background level extracted from each image. Bottom panel: simulated 10 ks XMM pointings showing a cluster with a core radius r_c = 20″ and count rate CR = 0.1 cts s⁻¹. For the contaminated cluster, 50% of the overall source counts lie within the central point source. The colour bar shows the number of photons within each pixel (2.5″ per pixel scale).