Velocity widths of the Hα emission, which have the component of instrumental velocity width (294 km s⁻¹) removed in quadrature. The four points on the right have a velocity width less than the instrumental velocity and are unresolved with velocity widths of less than 150 km s⁻¹. Angular distances in arcseconds are relative to the centre of the BCG, taken along position angle of 110°, running west to east (i.e. more positive with increasing RA) and centred on the peak (at 0″), corresponding to the white region displayed in the left-hand panel of Fig. 3.