From top to bottom: O I 1355.6 Å, Si IV 1393 Å and C II 1336 Å average spectral profiles. The observed spectral lines (black curves) are averaged over the entire QS FoV taken on 12 November 2020. The best fit with a Gaussian is shown in red. Error bars on the black curves represent the standard deviation of the intensity at each wavelength point, computed across all spatial pixels in the QS FoV. Intensities are given in units of [erg cm⁻² s⁻¹ sr⁻¹ Angstrom⁻¹].