Discovery of a relativistic Fe line in PG 1425+267 with XMM-Newton and study of its short time-scale variability

We report results from the XMM-Newton observation of the radio-loud quasar PG 1425+267 (z= 0.366). The X-ray data above 2keV exhibit a double-peaked emission feature in the Fe K band. The higher energy peak is found at 6.4keV and is consistent with being narrow, while the lower energy one is detected at 5.3keV and is much broader than the detector resolution. We confirm the significance of the detection of the broad red part of the line via Monte Carlo simulations (99.1 per cent confidence level). We explore two possible origins of the line profile, i.e., a single relativistic iron line from the accretion disc, and the superposition of a narrow 6.4-keV line from distant material and a relativistic one. We find that a contribution from a distant reflector is not required by the data. We also perform a time-resolved analysis searching for short time-scale variability of the emission line. Results tentatively suggest that the line is indeed variable on short time-scales (at the 97.3 per cent confidence level according to simulations) and better quality data are needed to confirm it on more firm statistical grounds. We also detect clear signatures of a warm absorber in the soft X-ray energy band.