a) X-ray photon spectral index as a function of intrinsic λ_2−10keV. The observational data correspond to the best fits of the high-quality observations described in Sect. 3. The gray regions indicate the location of solutions for the model with seed photons from thermal synchrotron only lower and including nonthermal synchrotron (of pion-decay or directly accelerated electrons; upper region). Ticks in the top axis show the approximate value of r_tr (see text). The thick vertical line indicates the maximum luminosity for the standard ADAF solutions (i.e., unaffected by the Coulomb cooling of protons). b) λ_1−10GeV as a function of λ_2−10keV, see Tables 1 and 2 for the observational data. The solid lines are for model N with δ = 10^-3, a = 0.95, β = 9 (triangles), model N with δ = 0.5, a = 0, β = 9 is plotted with circles), model H_0.1 with δ = 10^-3, a = 0.95, β = 9 with squares, and all three are the same as in Fig. 2b below. The dashed line with open squares denotes the rest-frame 1–10GeV luminosity in the last model (i.e., H_0.1). In panel b), λ_2−10keV corresponds to the average X-ray luminosity during the Fermi/LAT observations (see text). This differs in some objects by up to a factor of 2 relative to panel a). The point for Cyg X-1 shows the hard state parameters according to Malyshev et al. (2013).