Reconstructed light curve of the giant flare of SGR 1806-2 using a smoothness-enforcing prior, with σ_sm = 5 × 10⁵. The grey narrow rectangle indicates the operational down time of the instrument. For better visibility, we plot the light curve between ≈164 s and ≈174 s in Figure 1b. In addition to the raw photon counts (black dots), the black line indicates the reconstruction of the expected photon counts, i.e. λ as well as its one-σ confidence interval. Owing to the high resolution of the photon flux, only every fourth point of the regular grid is plotted. In both plots each pixel has a duration of 1∕800 s.