Comparison of S1D spectrum with two ESPRESSO echelle orders before (top left panel) and after (bottom left panel) blaze correction. Top right panel: compares the normalized S1D spectrum with the normalized S2D adjacent orders for a small spectral region in which the two orders overlap. The inset plot shows the zoom of the core of the strongest spectral linein the region. Middle-right and bottom-right panels: division of the two orders and the division of the left order by theS1D spectrum, respectively.