Fraction of X-ray bright galaxies as a function of the distance from the cluster centre in units of R₂₀₀. Left panel: black solid squares represent Bullet cluster X-ray sources with 0.5–8 keV flux > 1 × 10⁻¹⁴ erg cm⁻² s⁻¹ and red open squares indicate the sample of 42 cluster by Ehlert et al. (2014). The average field AGN fraction in the COSMOS–Legacy survey is denoted by a blue solid line; 1σ uncertainties are identified by the dashed region. Right panel: Black squares represent Bullet cluster sources with 0.5–2 keV flux ≥3 × 10⁻¹⁶ erg cm⁻² s⁻¹. The average field AGN fraction in the CDF-S 4 Msec survey is denoted by a blue solid line; 1σ uncertainties are identified by the dashed region.