BeppoSAX confirms extreme relativistic effects in the X-ray spectrum of   MCG-6-30-15
  We report the first simultaneous measure of the X-ray broadband (0.1--200 keV) continuum and of the iron K-alpha fluorescent line profile in the Seyfert 1 galaxy MCG-6-30-15. Our data confirms the ASCA detection of a skewed and redshifted line profile (Tanaka et al. 1995). The most straightforward explanation is that the line photons are emitted in the innermost regions of a X-ray illuminated relativistic disk. The line Equivalent Width (~200 eV) is perfectly consistent with the expected value for solar abundances, given the observed amount of Compton reflection. We report also the discovery of a cut-off in the nuclear primary emission at the energy of ~160 keV. 
M.Guainazzi (1), G.Matt (2), S.Molendi (3), A.Orr (1), F.Fiore (4,5),   P.Grandi (6), A.Matteuzzi (5), T.Mineo (7), G.C.Pero...