Detection limit as a function of the redshift (z), as detectable by a standard LoTSS observation (Eq. (7)). Different lines show the dependence of the radio power on different spectral indices (solid, α = −1.5; dot-dashed, α = −1.0; dashed, α = −1.3; dotted, α = −1.8). The colour bar and the coloured bands refer to the mass that a galaxy cluster should have to lie exactly on the P_150 MHz − M₅₀₀ correlation found by Cuciti et al. (2023). Clusters from the MaDCoWS-LoTSS DR2 sample are also displayed (detections with golden stars, and non-detections with low-vertices triangles).