Process of telluric absorption correction of the CARMENES spectra using molecfit. The panels show zooms into regions where the main absorbers are, those being O₂, H₂O, CO₂ and CH₄, from top to bottom respectively. The modelled telluric transmission spectrum is presented as a solid black line, shifted vertically for clarity, where the zero flux level is indicated with the dashed line. In the bottom panel some sky emission lines are clearly visible, which are masked at the analysis stage.