(a) Synthetic high-resolution spectrum of HAT-P-7b over a wide wavelength range, assuming a cold thermosphere scenario with 5000 K. (c) Similar to (a) except ion are excluded. (e) The difference between (a) and (c) that shows the significance of ion signatures. (b), (d), and (f) are similar to (a), (c), and (e) but assuming a hot thermosphere with 10 000 K. The pronounced ions are marked in the differential spectrum panels, (e) and (f).