  X-ray reflection models are used to constrain the properties of the accretion
disk, such as the degree of ionization of the gas and the elemental abundances.
In combination with general relativistic ray tracing codes, additional
parameters like the spin of the black hole and the inclination to the system
can be determined. However, current reflection models used for such studies
only provide angle-averaged solutions for the flux reflected at the surface of
the disk. Moreover, the emission angle of the photons changes over the disk due
to relativistic light bending. To overcome this simplification, we have
constructed the new angle-dependent reflection model RELXILL, by
self-consistently connecting the XILLVER reflection models with the
relativistic blurring code RELLINE.
