Phase-resolved spectral parameters obtained from the fits to the XMM-Newton data. The pulse profile is extracted in 350 bins, while the spectra are extracted in 128 bins (0.5−10 keV). Filled squares in the parameter panels indicate a frozen parameter value. The reduced χ² is computed with a number of degrees of freedom of between 99 and 199, depending on the statistics of the different spectra. Uncertainties are reported at 90% c.l. for all parameters.