Iron Kα line intensity from accretion discs around rotating black holes

Abstract

We calculate the iron fluorescent Kα line intensity from an accretion disc orbiting around a maximally rotating black hole and illuminated by an X-ray source located on the hole rotation axis. We find that the line intensity can be much greater than that obtained from illuminated accretion discs around static black holes. This provides a possible explanation for the large iron line equivalent widths observed in some Seyfert 1 galaxies.