Spectrum of Cen X-3 as seen by NuSTAR and Swift. a: unfolded spectrum and the different components of the BWsim best-fit model. The difference between the unfolded data points and the model is caused by the algorithm used to unfold the data. In black the full spectrum is shown and colored are the different components. b: spectrum fitted with BWsim. Red and orange indicate the data from the two focal plane modules of NuSTAR and shown in dark and light blue is the Swift data in window timing and photon counting mode. c–e: residuals for the FDcut, HighEcut and the BWsim model.