Publikace ÚTF

Light from a distant quasar passing in the vicinity of a foreground galaxy gets deflected by its gravitational field. According to Fermat’s principle several macro-images of the quasar can then be observed. In addition, the light may be affected by the gravitational field of individual stars moving in the lensing galaxy, creating multiple micro-images. We cannot resolve them because of their small angular separation, but we can observe an associated increase in the source flux due to microlensing. We use simulations to show how the prominent X-ray iron Kα line is affected during the microlensing event. We describe in detail the underlying numerical integration involving divergent integrands.