Monochromatic radiative energy exchange rate Q_v (values shown in the colour-bars) computed using the opacities from Fig. 2 for the models of the same four stellar types versus wavelength (horizontal axis) and geometrical height (vertical axis). Labels and overploted lines are same as in Fig. 2. The colour-bar values of each star range from – max |Q_v| to max |Q_v|. Blue tones in the colour-map correspond to negative Q_v, i.e. cooling in the atmosphere, and red tones correspond to positive Q_v, i.e. heating.