Panel a: flare lightcurve (black, solid) for data observed between 0.5 and 1.0 keV. The red, dashed line shows the fit when the decay of the sinusoid was described by an exponential, while the blue, dot-dashed curved shows the fit when the decay of the sinusoid was described by a Gaussian. We note that the blue and red curves are almost identical and, therefore, difficult to distinguish. Panel b: flare lightcurve (black, solid) for data observed between 4.5 and 12.0 keV. No good fitcontaining QPPs was obtained for this data set and so the green dot-dashed line shows the best fitting exponential decay as described by Eq. (1).