HST continuum corrected Hα image taken from Östlin et al. (2009), with the red shifted and blue shifted MUSE Hα velocity map overlayed as contours (Fig. 8). The red contours show the velocity contours of 20, 30 and 40 km s⁻¹, while the blue contours show the velocities −10, −20 and −30 km s⁻¹. The zoom in shows the central 1□ kpc around cluster 23. The HST map shows the bubble around cluster 23 and the hole in that bubble towards the north.