A high-velocity ionized outflow and XUV photosphere in the narrow emission line quasar PG1211+143

We report on the analysis of a ~60-ks XMM-Newton observation of the bright, narrow emission line quasar PG1211+143. Absorption lines are seen in both European Photon Imaging Camera and Reflection Grating Spectrometer spectra corresponding to H- and He-like ions of Fe, S, Mg, Ne, O, N and C. The observed line energies indicate an ionized outflow velocity of ~24 000 km s^-1. The highest energy lines require a column density of N_H~ 5 × 10²³ cm^-2, at an ionization parameter of logξ~ 3.4. If the origin of this high-velocity outflow lies in matter being driven from the inner disc, then the flow is likely to be optically thick within a radius of ~130 Schwarzschild radii, providing a natural explanation for the big blue bump (and strong soft X-ray) emission in PG1211+143.