Top: Velocity of the BGG – host of WAT radio galaxy 10913, relative to the IGM as a function of the jet density in cm⁻³. The light-grey region denotes the range of possible values and solid curves represent limiting cases: R = 77 kpc, v_j = 0.7c (red), and R = 109 kpc, v_j = 0.58c (blue). Vertical dashed lines indicate jet density bounds: ρ_j, min = 10⁻⁴ρ_IGM and ρ_j, max = 10⁻²ρ_IGM. In the lower right, the narrow range around ρ_j, min is enlarged, revealing the minimum v_BGG/IGM for the two limiting cases (red and blue color). Bottom: LoS peculiar velocities (redshifts) of the hosts of radio galaxies 10913 (BGG) and 44 compared to the (group) center of the Gaussian fit to 23 high confidence group members (see text for details).