In the top panels, the dark matter (left), gas (centre) and stars particles (right) mass distribution for the most massive disturbed halo at redshift z = 0.1 of the Illustris TNG simulations. We also show the BCG's position and the centre-of-mass of gas cells in the central panel; we can see that the position of the centre-of-mass is located around 0.4R₂₀₀ measured from the position of the BCG. In the bottom panels, similar to the top panels, the distribution of the different components for the most massive relaxed halo at the same redshift.