Radial velocity and Mach number structure in the cluster-filament interface. Top left panel: Radial velocity structure around filament F1 (white dots). Negative (positive) values correspond to gas inflow (outflow). The values are averages in each sight line and thus the image is illustrative rather than quantitatively accurate. The black symbols indicate the boundary of the virial region. The grey surface marks the radius r = 1.5r₂₀₀ from the cluster centre. Top right panel: Radial velocity repeated from Fig. 5. Bottom left panel: Radial Mach number structure around filament F1 (black dots). The subsonic regions (values below 1) are shown in blue and supersonic regions in white, i.e. in the 2D projection white regions indicate the lack of subsonic gas along the line of sight. Bottom right panel: Median ratio of bulk to sound velocity (a proxy for Mach number) of the gas outside the virial boundary as a function of distance from the cluster centre.