Fits to the profiles of the 2008 (top) and the 2005 (middle) γ-ray flares by exponential functions as described by Eq. (1). The selected number of terms N_exp were chosen so that the reduced χ²-statistic was minimized (bottom). The best-fit values are given in Tables 1 and 2. An alternative fit is given for the 2008 flare with a similar χ², that accounts for the double peak at the beginning with a single exponential term. The vertical lines mark the epochs whose SED was analyzed in Sect. 4.4, as in Fig. 1.