Segments of the observations at the energy of 4.1 keV with a time bin size of 0.5 s: G-1 observation is shown in the left panel, G-2 in the central panel, and G-3 in the right panel. The vertical red lines mark the position of the maxima to better illustrate the variations in the duration of the bursts. We note that the time separation between vertical lines is not constant and that the peaks present different shapes in the three observations.