Andy Fabian -- IOA Cambridge

Broad X-ray iron lines and the strong gravity of black holes

X-ray spectra from ASCA commonly show that the iron-K line from Seyfert
1 active galaxies is very broad and skew. This is characteristic of
emission from a disk orbiting at a few Schwarzschild radii of a black
hole. The line profile can reveal the disk inclination, inner radius and
geometry. I shall review the observations made so far and demonstrate
that the spin of at least one black hole may have been determined in
this way. Finally I shall discuss the potential for X-ray reverberation
mapping of the inner regions of disks around black holes which may yield
masses and spins of a wide range of black holes and, eventually, their
mass and spin evolution.