Fits in the oxygen region. Here only RGS1 of the most recent observation is displayed for clarity. Upper panel: comparison between a fit only in terms of gas (solid line) and the best fit obtained using dust (dashed line). For comparison an unacceptable fit using olivine (dashed-dotted line) is also displayed. Lower panel: comparison between a fit only in terms of gas (solid line) and the best fit obtained with a mixture of gas and dust (dashed line). See more details in the text.