X-ray Line Profile Variations During Quasar Microlensing

Observations of gravitationally lensed quasars have revealed X-ray line profile variations occurring during microlensing events. We simulate the effect using a simple model: a microlensing fold caustic crossing a spatially resolved model of Fe Kα line emission from a thin accretion disk around a Kerr black hole. We demonstrate the appearance of additional peaks and edges in the line profile. We illustrate the underlying mechanism of their generation and derive analytical expressions for their shape.