X-ray luminosity, L_X, as a function of bolometric luminosity, L_bol, for the eRASS1-detected stars colour coded by the log(L_X/L_bol). Circles and triangles indicate sources with log(L_X/L_bol) ≥ −5 and log(L_X/L_bol) < −5, respectively. In our flux-limited sample, the former group is dominated by coronally active stars, while the latter is consistent with non-coronal (wind-driven) emitters. The dashed line represents the linear fit in log-log space for all the stars (indicated with large open circles), excluding OB-luminous, A-type, F-type and intermediate binaries, which are indicated with open squares.