Lessons learnt from INTEGRAL AGN
  The INTEGRAL mission provides a large data set for studying the hard X-ray
properties of AGN and allows to test the unified scheme for AGN. We present
results based on the analysis of 199 AGN. A difference between the Seyfert
types is detected in slightly flatter spectra with higher cut-off energies and
lower luminosities for the more absorbed/type 2 AGN. When applying a Compton
reflection model, the underlying continua (photon index 1.95) appear the same
in Seyfert 1 and 2, and the reflection strength is R=1 in both cases, with
differences in the inclination angle only. A difference is seen in the sense
that Seyfert 1 are on average twice as luminous in hard X-rays than the Seyfert
2 galaxies. The unified model for Seyfert galaxies seems to hold, showing in
hard X-rays that the central engine is the same in Seyfert 1 and 2 galaxies,
seen under different inclination angle and absorption. Based on our knowledge
of AGN from INTEGRAL data, we briefly outline open questions and investigations
to answer them. In this context an ultra-deep (>= 12 Ms) extragalactic field
can be a true legacy of the INTEGRAL mission in the area of AGN studies.
