Emission spectra, O₃ mixing ratio profiles, and temperature profiles for model atmospheres with 100%, 10%, 1%, and 0.1% PAL O₂ for all host stars. The depth of spectral features in emission spectra is dependent on the temperature difference between the absorbing and emitting layers of the atmosphere, causing the O₃ feature depth to strongly correlate with the temperature difference between the stratosphere and planetary surface. However, since O₃ is responsible for the majority of stratospheric heating, this results in higher O₃ abundances (with more stratospheric heating) having shallower spectral features than atmospheres with less O₃ and cooler stratospheres. For full details see Sect. 4.5. We note that temperatures for parts of the atmosphere above 1 mbar are held constant as that is the maximum height computed by the climate code (see Sect. 3.1 for more details).