Cyclotron lines in subcritical X-ray pulsars: Monte Carlo simulations reveal the origin of the observed variability

Prodromos Fotiadis, Nick Loudas, Nikolaos D. Kylafis +1

Observed cyclotron resonant scattering features (CRSFs) in X-ray pulsars (XRPs) exhibit strong variability. In the subcritical luminosity regime, the centroid energy ($E_{CRSF}$) a…