  XMM-Newton observations of the low luminosity, radio-quiet quasar Markarian
205 have revealed a unique iron K emission line profile. In marked contrast to
the broad and redshifted iron K line commonly seen in ASCA observations of
Seyfert 1 galaxies, we find that a substantial amount of the line flux in Mrk
205 occurs above the neutral line energy of 6.4 keV. Furthermore, we find that
the iron line emission has two distinct components, a narrow, unresolved
neutral line at 6.4 keV and a broadened line centred at 6.7 keV. We suggest
that the most likely origin of the 6.7 keV line is from X-ray reflection off
the surface of a highly ionised accretion disk, whilst the 6.4 keV component
may arise from neutral matter distant from the black hole, quite possibly in
the putative molecular torus. Overall this observation underlines the potential
of XMM-Newton for using the iron K line as a diagnostic of matter in the
innermost regions of AGN.
