Comparison of best-fitting model spectrum (red line) with re-normalized observation (black line; HIRES spectrum taken on December 12, 2017). Light colors mark regions that have been excluded from fitting, e.g., due to data reduction artifacts or the presence of features that are not properly included in our models such as disk emission in the cores of the hydrogen and helium lines or possible stratification effects in the helium lines. Residuals χ are shown as well.