Relation between the GRG projected proper length l_p and total luminosity density L_ν at rest-frame frequency ν = 144 MHz. Total luminosity densities include contributions from all available RG components (i.e. the core, jets, hotspots, and lobes). Literature GRGs are from Dabhade et al. (2020b) and are marked with grey disks, and Alcyoneus is marked with a green star. Translucent ellipses indicate −1 to +1 standard deviation uncertainties. Alcyoneus has a typical luminosity density (percentile 45 ± 3%).