Histogram of the total number of photons counts vs. RAWX for the original event file of the full observation (solid line) and for the event file from the deep-dipping time interval (dotted line). The defined source region RAWX = [28−48] and background region RAWX = [3−5] are indicated with vertical lines. The plot shows the background contamination by the source emission displayed by the difference in counts around the wings of the distributions. Data shown for Obs. 301.