Representative pulse profiles of source normalized by dividing by the average source intensity in the frame using efold task as observed by NuSTAR in several energy bands (top), and the phase-energy matrix showing the energy evolution of the (normalized) pulse profiles in details (bottom). In the latter case, slices along the constant energy represent normalized pulse profiles similar to those shown in the top panel. We note the energy dependence of pulse profile shape, particularly around ∼15 keV.