Is the X-ray spectrum of the narrow emission line QSO PG1211+143 defined by its energetic outflow?

An XMM–Newton observation of the bright QSO PG1211+143 in 2001 revealed a blueshifted absorption line spectrum indicative of a high-velocity radial outflow of highly ionized gas. Unless highly collimated, the outflow mass rate was shown to be comparable to the accretion rate, with mechanical energy a significant fraction of the bolometric luminosity. Analysis of the full XMM–Newton data set now allows the wider effects of that energetic outflow to be explored.We find that absorption and re-emission of the primary continuum flux in the ionized outflow, together with a second, less strongly absorbed, continuum component can explain the strong ‘soft excess’ in PG1211+143 without the extreme velocity ‘smearing’ in conflict with observed absorption line widths. Previously unpublished data from a second XMM–Newton observation of PG1211+143 is shown to be consistent with the new spectral model, finding that the additional continuum component dominates the spectral variability.We speculate that this variable continuum component is powered by the high-velocity outflow

Fe K emission and absorption features in XMM-Newton spectra of Markarian 766: evidence for reprocessing in flare ejecta

We report on the analysis of a long XMM–Newton European Photon Imaging Camera (EPIC) observation in 2001 May of the narrow-line Seyfert 1 galaxy Markarian 766 (Mrk 766). The 3–11 keV spectrum exhibits a moderately steep power-law continuum, with a broad emission line at 6.7 keV, probably blended with a narrow line at 6.4 keV, and a broad absorption trough above 8.7 keV. We identify both broad spectral features with reprocessing in He-like Fe. An earlier XMM–Newton observation of Mrk 766 in 2000 May, when the source was a factor 2 fainter, shows a similar broad emission line, but with a slightly flatter power law and absorption at a lower energy. In neither observation do we find a requirement for the previously reported broad 'red wing' to the line and hence of reflection from the innermost accretion disc. More detailed examination of the longer XMM–Newton observation reveals evidence for rapid spectral variability in the Fe K band, apparently linked with the occurrence of X-ray 'flares'. A reduction in the emission line strength and increased high-energy absorption during the X-ray flaring suggests that these transient effects are due to highly ionized ejecta associated with the flares. Simple scaling from the flare avalanche model proposed for the luminous quasi-stellar object PDS 456 confirms the feasibility of coherent flaring being the cause of the strong peaks seen in the X-ray light curve of Mrk 766

Swift and XMM-Newton observations of the dark GRB 050326

We present Swift and XMM-Newton observations of the bright gamma-ray burst GRB050326, detected by the Swift Burst Alert Telescope. The Swift X-Ray Telescope (XRT) and XMM-Newton discovered the X-ray afterglow beginning 54 min and 8.5 h after the burst, respectively. The prompt GRB050326 fluence was (7.7 ± 0.9) × 10−6 erg cm−2 (20–150 keV), and its spectrum was hard, with a power law photon index Γ = 1.25 ± 0.03. The X-ray afterglow was quite bright, with a flux of 7 × 10−11 erg cm−2 s−1 (0.3–8 keV), 1 h after the burst. Its light curve did not show any break nor flares between ~1 h and ~6 d after the burst, and decayed with a slope α = 1.70 ± 0.05. The afterglow spectrum is well fitted by a power-law model, suffering absorption both in the Milky Way and in the host galaxy. The rest-frame hydrogen column density is significant, NH,z >~4 × 1021 cm−2, and the redshift of the absorber was constrained to be z > 1.5. There was good agreement between the spatial, temporal, and spectral parameters as derived by Swift-XRT and XMM-Newton. By comparing the prompt and afterglow fluxes, we found that an early break probably occurred before the beginning of the XRT observation, similarly to many other cases observed by Swift. However, the properties of the GRB050326 afterglow are well described by a spherical fireball expanding in a uniform external medium, so a further steepening is expected at later times. The lack of such a break allowed us to constrain the jet half-opening angle ϑj >~7◦. Using the redshift constraints provided by the X-ray analysis, we also estimated that the beaming-corrected gamma-ray energy was larger than 3 × 1051 erg, at the high end of GRB energies. Despite the brightness in X rays, only deep limits could be placed by Swift-UVOT at optical and ultraviolet wavelengths. Thus, this GRB was a “truly dark” event, with the optical-to-X-ray spectrum violating the synchrotron limit. The optical and X-ray observations are therefore consistent either with an absorbed event or with a high-redshift one. To obey the Ghirlanda relation, a moderate/large redshift z >~ 4.5 is required