Density map for S​_ph as a function of T_eff, where darker colors correspond to higher density (consistent with the color code in Fig. 3). Each panel corresponds to a different Kepler magnitude interval: from bright (top left) to faint (bottom right). The lines represent the lower edge (5^th percentile) of the S​_ph distribution: solid line – the same magnitude of the density plot; dashed lines – other magnitude intervals, for reference. The color code of the lines also indicates the respective Kp.