Results of pulsed amplitudes and phase angles. Left panel: fractional amplitude of two harmonics (1 – fundamental, 2 – first overtone) as a function of energy using background corrected data from NICER (squares), XMM-Newton EPIC-pn (circles) and NuSTAR (triangles). The pulsed fraction of the fundamental component increases from ∼4% till ∼7.5% from 1 to 5 keV, from where it more or less saturates at a level of ∼7.5%. Right panel: phase angles ϕ_k (divided by 2π) for the two Fourier components as function of energy. They remain remarkably stable across the 1–60 keV band, with possibly a small drift for ϕ₁ to slightly lower values at energies above ∼10 keV.