Observer frame light curves in the Swift/XRT band (0.3−10 keV) resulting from different parameter sets. The black solid line in both panels shows the fiducial light curve resulting from Maxwellian electron injection obtained with the same parameters as the spectra in Fig. 8. The green dash-dot-dot-dot line in the top panel represents the emission due to a power-law electron injection function. The other curves represent simulations with a Maxwellian injection term where one parameter at a time is varied from the fiducial value. In the top panel, the dotted (dashed) lines show the light curves when the blast energy E₀ (external density n₀) is increased/decreased by a factor of 100 (10). In the bottom panel, the long-dashed (dash-dot) lines correspond to the emission when the electron energy fraction ϵ_e (magnetic energy fraction ϵ_B) is increased/decreased by a factor of 10 (100).