Gas density maps in the three main projection axes (z, y, and x simulation axis, from left to right) at z = 0.07. Each map, centred on the cluster pair, encloses a cubic volume of 20 h⁻¹ cMpc per side. We overplot in red, yellow, and blue the spatial trajectories of the gas particles that are finally selected within R₅₀₀ of GC1 and GC2 and in the bridge at z = 0.07. Each trajectory shows a colour gradient with time, from dark at z ~ 2 to light at z= 0.07.