Left: same map as in Fig. 2 but with the contours of the logarithm of the vertical average coronal temperature (in Kelvin, blue solid line) and the contours of the photon indices of the output spectrum produced by the corona (black dot-dashed lines). The other parameters are fixed to T_bb = 10⁵ K, ξ₀ = 10³ erg s⁻¹ cm, and n_H = 10¹² cm⁻³. Similarly to Fig. 2 the green line corresponds to the condition χ = 1. The darkened area corresponds to the usual observational constraints of the temperature (0.1–2 keV) and photon index (2.2–3.2) of the soft X-ray excess. Right: vertical coronal temperature profiles for τ_cor = 20 and χ = 1.35 and 0.753. The corresponding average temperatures are indicated for each temperature profile.