Evidence of a high-velocity ionized outflow in a second narrow-line quasar PG 0844+349

Pounds, K. A.; King, Andrew; Page, K. L.; O’Brien, P. T.

doi:10.1111/j.1365-2966.2003.07164.x

Cited by 150 publications

(125 citation statements)

References 22 publications

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“…We cannot confirm the strong spectral signatures taken by Pounds et al (2003b) as evidence for high velocity outflow from the source.…”

Section: Discussioncontrasting

confidence: 39%

“…The physical reality of such a structure can only be assessed by an observation yielding high energy data with considerably higher signal to noise; however, if it is real, this absorption structure can be due to a fortuitous combination of outflow velocity and red-shift in the source, or it might be due to hot local gas. This possibility was pointed out by McKernan et al (2004) for the identification of the low energy structures found in the RGS spectra of PG 0844+349 by Pounds et al (2003b).…”

Section: Discussionmentioning

confidence: 99%

“…A second case for outflow from a narrow line Seyfert galaxy (NLS1) has been claimed by Pounds et al (2003b) for PG 0844+349 from an observation of about 20 ks by XMM-Newton. The absorption features in the ∼9−13 Å band, as well as at ∼3.0 keV and ∼8.2 keV, were not seen in the original analysis of the data by Brinkmann et al (2003); however, different versions of instrument responses had been used.…”

Section: Introductionmentioning

confidence: 99%

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PG 0844+349 revisited – is there any outflow?

Brinkmann

Wang

Grupe

et al. 2006

A&A

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Aims. The detection of high velocity absorption lines from highly ionized material has been reported recently from the X-ray spectrum of the narrow line Seyfert 1 galaxy PG 0844+349 and were interpreted as a relativistic outflow from the source. We studied this outflow because it would have important implications for our understanding of narrow line Seyfert 1 galaxies. Methods. To address the reality of these absorption features, we analyzed a long XMM observation with the MOS cameras on this object. Results. We did not detect the absorption lines claimed, and a re-analysis of the previous data set with the most recent detector calibrations did not confirm the earlier results. The X-ray spectra can be well modeled with a power law plus a bremsstrahlung component. With this description, the soft and the harder 2−10 keV X-ray flux changed by a similar fraction ( 25%) between the two observations with only small changes in the spectral form. An analysis of the hardness ratio variations within a single observation does not show any strong correlation between the hardness ratio and the continuum luminosity and we do not detect substantial lags between the hard and soft band fluxes.

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“…We cannot confirm the strong spectral signatures taken by Pounds et al (2003b) as evidence for high velocity outflow from the source.…”

Section: Discussioncontrasting

confidence: 39%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

PG 0844+349 revisited – is there any outflow?

Brinkmann

Wang

Grupe

et al. 2006

A&A

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“…Recent XMM-Newton observations of bright quasars (Pounds et al 2003a(Pounds et al , 2003bReeves et al 2003) give strong evidence for powerful outflows from the nucleus with mass ratesṀ out $ M yr À1 $Ṁ Edd and velocity V $ 0:1c (i.e., ¼ 0:1) in the form of blueshifted X-ray absorption lines. These outflows closely resemble those recently inferred in a set of ultraluminous X-ray sources with extremely soft spectral components (Mukai et al 2003;Fabbiano et al 2003).…”

Section: Discussionmentioning

confidence: 99%

Effects of Downscattering on the Continuum and Line Spectra in a Powerful Wind Environment: Monte Carlo Simulations, Analytical Results, and Data Analysis

Laurent

Titarchuk

2007

ApJ

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In an earlier paper, the general formulation and results for photon reprocessing (downscattering) that included recoil and Comptonization effects due to divergence of the flow were presented. In a second paper we showed the Monte Carlo (MC ) simulated continuum and line spectra. We also provided an analytical description of the simulated continuum spectra using the diffusion approximation. We have simulated the propagation of monochromatic and continuum photons in a bulk outflow from a compact object. Electron scattering of the photons within the expanding flow leads to a decrease of their energy, which is of first order in V /c (where V is the outflow velocity). The downscattering effect of first order in V /c in the diverging flow is explained by semianalytical calculations and confirmed by MC simulations. We conclude that redshifted lines and downscattering bumps are intrinsic properties of the powerful outflows for which the Thomson optical depth is greater than 1. We fitted our model line profiles to the observations using four free parameters, ¼ V /c, the optical depth of the wind , the wind temperature kT e , and the original line photon energy E 0 . We show how the primary spectrum emitted close to the black hole is modified by reprocessing in the warm wind. In the framework of our wind model, the fluorescent iron line K is formed in the partly ionized wind as a result of illumination by central source continuum photons. The demonstrated application of our outflow model to the XMM-Newton observations of MCG À6-30-15 and to the ASCA observations of GRO J1655À 40 points out a potential powerful spectral diagnostic for probes of the outflowYcentral object connection in Galactic and extragalactic black hole sources.

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“…These objects are: PG 1211+143 (Pounds et al 2003a with an outflow of ∼ 24, 000 km s −1 , PG 0844+349 (Pounds et al 2003b) with an outflow of ∼ 60, 000 km s −1 , and PDS 456 (Reeves et al 2003) with an outflow of ∼ 50, 000 km s −1 . Detection of absorption lines in outflow with grating spectra is of vital importance as one can detect numerous lines in several ions, enhancing the statistical significance of the detection.…”

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confidence: 99%

The Variable High-Velocity Outflows Seen in X-Ray Spectra

Kaspi

2009

Proc. IAU

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Abstract. Several AGNs have been reported to have ultra-high velocity (UHV) outflows (of order 0.3 v/c 0.05) that are detected in their X-ray spectrum. Re-visiting these outflow observations reveal that the spectrum has changed along with the claimed outflows. The luminous quasar PDS 456 is the brightest AGN in which a UHV outflow has been claimed to be present in its grating spectrum. We report on an XMM-Newton observation of this source, as well as analysis of past observations, which reveal its variable nature and the variable nature of UHV outflows. In this object, as well as in a few others, repeated observations failed to reproduce the previous absorption spectra. This indicates that variability is common among the UHV winds. A discussion of the reality, significance, and the interpretation of the UHV outflow phenomenon is presented. If UHV outflows exist, they might be a transiting phenomenon, as indicated from repeated observations, and this has to be taken into account when studying the influence of these outflows on the surrounding galaxy.

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Evidence of a high-velocity ionized outflow in a second narrow-line quasar PG 0844+349

Cited by 150 publications

References 22 publications

PG 0844+349 revisited – is there any outflow?

PG 0844+349 revisited – is there any outflow?

Effects of Downscattering on the Continuum and Line Spectra in a Powerful Wind Environment: Monte Carlo Simulations, Analytical Results, and Data Analysis

The Variable High-Velocity Outflows Seen in X-Ray Spectra

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