We present XMM-Newton observations of the high redshift ( z = 3.104 ) , radio-loud quasar PKS 0537 - 286 .
The EPIC CCD cameras provide the highest signal-to-noise spectrum of a high-z quasar to date .
The EPIC observations show that PKS 0537 - 286 is extremely X-ray luminous ( L _ { X } = 2 \times 10 ^ { 47 } erg s ^ { -1 } ) , with an unusually hard X-ray spectrum ( \Gamma = 1.27 \pm 0.02 ) .
The flat power-law emission extends over the whole observed energy range ( 0.4 to 40 keV in the quasar rest frame ) ; there is no evidence of intrinsic absorption , which has been claimed in PKS 0537 - 286 and other high z quasars .

However , there is evidence for weak Compton reflection .
A redshifted iron K line , observed at 1.5 keV - corresponding to \sim 6.15 keV in the quasar rest frame - is detected at 95 % confidence .
If confirmed , this is the most distant iron K line known .
The line equivalent width is small ( 33eV ) , consistent with the ‘ X-ray Baldwin effect ’ observed in other luminous quasars .
The reflected continuum is also weak ( R \mathrel { \hbox { \hbox to 0.0 pt { \hbox { \lower 4.0 pt \hbox { $ \sim$ } } } { \raise 2.0 pt% \hbox { $ < $ } } } } 0.25 ) .
We find the overall spectral energy distribution of PKS 0537 - 286 is dominated by the X-ray emission , which , together with the flat power-law and weak reflection features , suggests that the X-radiation from PKS 0537 - 286 is dominated by inverse Compton emission associated with a face-on relativistic jet .

alaxies : active – quasars : individual : PKS 0537 - 286 – X-rays : galaxies