ESPRESSO wiggle correction. Top panels: periodogram cumulated over all transmission spectra before (left) and after (middle) correction. Right panels show the ratio between the RMS of the transmission spectra and their median error before (red) and after (blue) correction. Bottom panel: example transmission spectrum as a function of light frequency, before (top, overplotted with the best-fit wiggle model in red with its dominant blue and secondary orange components) and after (bottom) correction.