Comparison between a model using a combination of WAs and CIA as opposed to WAs alone. Upper panel: Transmission plot. Transmission is defined as the observed spectrum divided by the continuum. This plot compares the behaviour of the CIA (red) around the 13 − 20 Å region in comparison to a WA with log ξ ∼ 0.96 (blue). The transmissions obtained by the other WAs used in both models are shown in fainter red and blue. Upper middle panel: Difference between a model implementing WAs and CIA (red) as opposed to WAs alone (blue). “WAs and CIA” is used to indicate our best-fit model. “WAs” is meant to represent the model with three WAs and no CIA. It is apparent that the latter case creates additional absorption in the 17 − 18 Å region. The most prominent absorption features identified by our models are marked and labelled. Lower middle panel: Residuals of the CIA and WA model. Lower panel: Residuals of the WAs model.