Soft band luminosity distribution of the eRASS1 clusters with redshift shown on the left panel. We only show the luminosities with significant detection at a >2σ confidence for demonstration purposes. The flux value of 4 × 10⁻¹⁴ erg s⁻¹ cm⁻² is overplotted as the dashed line. We do not use a flux limit to select clusters; the flux limit is plotted here as a reference. On the right panel, flux within 300 kpc is displayed as a function of exposure time. We only present the significant flux detections with detection confidence >2 σ; the upper limits are excluded from the figure. The color bar indicates z_best. The figure demonstrates that the detection of sources depends on the survey’s depth.