Photon spectral index vs. F₁₀₀ for five phases of the outburst: pre-flare, plateau, flare I, flare II, and post-flare, as defined in Table 2. Left panel: fluxes are calculated with PL model of photon index Γ. Right panel: fluxes are calculated with BPL model of photon indices ﹩{{\rm{\Gamma }}}_{1}\,\mathrm{and}\,{{\rm{\Gamma }}}_{2}﹩. Values are reported in Table 5.