Color-coded maps of the pulse phase distribution of normalized countrates in regions I − IV as indicated in Fig. 2. See text for details. Color represents the number of measurements for each countrate in the respective phase bin. Each phase bin was normalized to itself, so that they have all comparable color-codes. Colors are ranging from violet, corresponding to zero, to red, corresponding to one. The superimposed black line shows the mean value, i.e., the pulse profile.