Confirming the high velocity outflow in PG 1211+143

Abstract

An XMM-Newton observation of the bright QSO PG1211+143 was previously reported to show evidence for a massive, energetic outflow, with an outflow velocity of v~0.1c based on the identification of blue-shifted absorption lines detected in both EPIC and RGS spectra. Subsequently, an order-of-magnitude lower velocity has been claimed from an ion-by-ion model fit to the RGS data. We show here, in a re-analysis of the higher signal-to-noise EPIC data, that the high velocity is confirmed, with the resolution of additional absorption lines yielding a revised outflow velocity in the range ~0.13-0.15c. Confirmation of a massive and energetic outflow in a non-BAL AGN has important implications for metal enrichment of the IGM and for the feedback mechanism implied by the correlation of black hole and galactic bulge masses. We note the near-Eddington luminosity of PG1211+143 may be the critical factor in driving such an energetic outflow, a situation likely to be common in AGN at higher redshift.