X-ray luminosity in the 0.2−2.3 keV band scaled by the SFR in the function of the sSFR for the full sample of normal galaxies, selected in this work, both quiescent (red dots) and SFGs (blue dots). The solid black line represents the observed fit of the sources, while the red solid line represents the completeness corrected fit. Lehmer et al. (2016) fit at z = 0.09 is pictured as a black dashed line, with the shaded region representing the 3σ dispersion. The size of the dots scales with the redshift of the sources Sect. 6.