Energy-resolved pulse profiles of accreting pulsars: Diagnostic tools for spectral features

We introduce a method for extracting spectral information from energy-resolved light curves folded at the neutron star spin period (known as pulse profiles) in accreting X-ray binaries. Spectra of these sources are sometimes characterized by features superimposed on smooth continuum, such iron emission lines and cyclotron resonant scattering features. address here question how to derive quantitative constraints energy-dependent changes profiles. developed robust determining each energy-selected bin value pulsed fraction using fast Fourier transform opportunely truncated number harmonics needed satisfactorily describe actual profile. determined uncertainty this sampling through Monte Carlo simulations total 1000 faked rebinned profiles have constant minimum signal-to-noise ratio throughout whole energy band. Finally we characterize dependence phenomenological polynomial model search corresponding signatures or Gaussian line apply our representative sample NuSTAR observations well-known pulsars. show that, with method, it is possible spectra, constrain position widths precision comparable results. also explore harmonic decomposition, correlation, lag spectra might be used additional probes detection characterization