The soft X-ray spectrum of the luminous narrow line Seyfert galaxy PG 1211+143 - evidence for a second high-velocity outflow component

Abstract

An XMM-Newton observation of the luminous Seyfert galaxy PG 1211+143 in 2001 revealed the first clear evidence for a highly ionized high-speed wind (in a non-broad absorption line active galactic nucleus), with a velocity of v ∼ 0.09c based on the identification of blueshifted absorption lines in both EPIC and Reflection Grating Spectrometer (RGS) spectra. A subsequent analysis of EPIC spectra, including additional absorption lines, led to an upward revision of the wind speed to ∼0.14c, while broad-band modelling indicated the need for a second, partial covering absorber to account for continuum curvature and spectral variability. We show here, in a new analysis of the XMM-Newton RGS data, that this additional absorber is detected in the soft X-ray spectra, with the higher spectral resolution providing a much improved velocity constraint, with v ∼ 0.07c. Similar variability of the ∼0.07c and ∼0.14c outflow components suggests they are physically linked, and we speculate that occurs by the fast (primary) wind impacting on small clumps of higher density, slow-moving matter close to the disc. We show that strong, velocity broadened soft X-ray emission features, located at the redshift of PG 1211+143, indicate the extended scale of the ionized outflow.