Mock X-ray (left) and radio (right) observations of the same simulated box of Fig. 1, located at z ≈ 0.05. The left panel shows the photon counts for a 1 Ms integration in the [0.8–1.2] keV band using WFI (see Sect. 2.2.1 for details) while the right panel gives the result of a mock radio survey at 260 MHz with the SKA-LOW (see Sect. 2.2.2 for details), in units of [Jy arcsec⁻²]. Each panel covers ∼28.4 ° ×28.4° in the sky. Both images include the noise level expected for the respective instrument, band, and integration time (in the case of SKA-LOW, we also consider the confusion noise level).