Maps of the limiting magnitude in the z band for sources detected with 10σ significance. The footprint maps show the coverage for the Legacy Surveys DR10 south (top panel) and DR9 north (bottom panel). Only regions with data in all the g-, r-, and z-bands were considered. The half sky that is covered by eRASS1 corresponds to the region below the red line. The limiting magnitudes in the z band directly translate to the limiting redshift z_vlim (see Appendix B for details).