Relativistic reflection in the average X-ray spectrum of AGN in the
  V\'eron-Cetty & V\'eron catalogue
  The X-ray spectra of active galactic nuclei (AGN) unveil properties of matter
around the super massive black hole (SMBH). We investigate the X-ray spectra of
AGN focusing on Compton reflection and fluorescence, important processes of
interaction between primary radiation and circum-nuclear material. Unresolved
emission lines (most notably the Fe line) in the X-ray spectra of AGN indicate
that this material is located far away from the SMBH. Contributions from the
inner accretion disk, affected by relativistic effects, have also been detected
in several cases.
  We studied the average X-ray spectrum of a sample of 263 X-ray unabsorbed AGN
that yield 419023 counts in the 2-12 keV rest-frame band distributed among 388
XMM-Newton spectra. We fitted the average spectrum using a (basically)
unabsorbed power law (primary radiation). From second model that represents the
interaction of the primary radiation with matter located far away from the
SMBH, we found that it was very significantly detected. Finally, we added a
contribution from interaction with neutral material in the accretion disk close
to the central SMBH, which is therefore smeared by relativistic effects, which
improved the fit at 6 sigma. The reflection factors are 0.65 for the accretion
disk and 0.25 for the torus. Replacing the neutral disk-reflection with
low-ionisation disk reflection, also relativistically smeared, fits the data
equally well, suggesting that we do not find evidence for a significant
ionisation of the accretion disk.
  We detect distant neutral reflection in the average spectrum of unabsorbed
AGN with z=0.8. Adding the disk-reflection component associated with a
relativistic Fe line improves the data description at 6 sigma confidence level,
suggesting that both reflection components are present. The disk-reflection
component accounts for about 70 % of the total reflected flux.
