Black hole winds

King, Andrew; Pounds, K. A.

doi:10.1046/j.1365-8711.2003.06980.x

Cited by 364 publications

(384 citation statements)

References 7 publications

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“…This adds to the well known evidence from the soft X-rays of a multi-phase warm absorber in Mrk 509 with log ξ ∼ 0.9-3.26 and N H ∼ 0.8−5.8 × 10 21 cm −2 (Smith et al 2007), and to the "intermediate" (log ξ ∼ 5.4, N H ∼ 5.8 × 10 22 cm −2 and v ∼ 0.05c) absorption component found by Ponti et al (2009) based on continuum variability arguments. Overall, Mrk 509 shows compelling evidence for a stratified absorber, as those predicted by hydrodynamical simulations of radiatively and/or magnetically driven outflows (Proga 2003;Proga & Kallman 2004;King & Pounds 2003;Murray et al 1995), but with ionizations and velocities up to extreme and challenging values. The extreme ionization parameter raises the question as to how much more fully ionised matter is included, but undetected yet, in the outflow, with its implications for the outflow mass-loss rates and energetics.…”

Section: Discussionmentioning

confidence: 60%

“…The velocities of these absorbers being often quite large, sometimes reaching mildly relativistic speeds (up to 0.2-0.4 c), suggests that we might be probing the extreme component of a wind/outflow that may well carry large amounts of mass into the interstellar medium (ISM) and/or intergalactic medium (IGM) at a rate comparable to, or even higher than the Eddington accretion rate (King & Pounds 2003;Reeves et al 2003;Chartas et al 2003;Pounds & Page 2006).…”

Section: Introductionmentioning

confidence: 99%

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X-ray evidence for a mildly relativistic and variable outflow in the luminous Seyfert 1 galaxy Mrk 509

Cappi¹,

Tombesi

Bianchi

et al. 2009

A&A

108

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Context. There is growing evidence for the presence of blueshifted Fe K absorption lines in a number of radio-quiet AGNs and QSOs. These may be fundamental to probe flow dynamics near supermassive black holes. Aims. Here we aim to verify and better characterise the existence of such Fe K absorption at ∼8-10 keV in the luminous Seyfert 1 galaxy Mrk 509, one of the most promising target for these studies.Methods. We present a comprehensive spectral analysis of the six XMM-Newton observations of the source (for a total of ∼200 ks), focusing on a detailed and systematic search for absorption features in the high-energy data. Results. We detect several absorption features at rest-frame energies ∼8-8.5 keV and ∼9.7 keV. The lines are consistent with being produced by H-like iron Kα and Kβ shell absorptions associated with an outflow with a mildly relativistic velocity of ∼0.14-0.2 c. The lines are found to be variable in energy and, marginally, in intensity, implying variations in either the column density, geometry and/or ionization structure of the outflow are common.

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Section: Discussionmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

X-ray evidence for a mildly relativistic and variable outflow in the luminous Seyfert 1 galaxy Mrk 509

Cappi¹,

Tombesi

Bianchi

et al. 2009

A&A

108

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“…It is worth mentioning that outflows have been invoked to account for the high luminosity in ULXs (e.g., Begelman 2002;King 2002;King & Pounds 2003) and the Compton-heated winds solution proposed here can be considered a variant of these models.…”

Section: A Mildly Relativistic Jet or A Compton Heated Wind?mentioning

confidence: 99%

XMM–Newtonobservations of the ultraluminous nuclear X-ray source in M 33

Foschini¹,

Rodríguez²,

Fuchs³

et al. 2004

A&A

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Abstract. We present observations with XMM-Newton of M 33 X-8, the ultraluminous X-ray source (L 0.5−10 keV ≈ 2×10 39 erg/s) closest to the centre of the galaxy. The best-fit model is similar to the typical model of Galactic black holes in very high state. Comparison with previous observations indicates that the source is still in a very high state after about 20 years of observations. No state transition has been observed even during the present set of XMM-Newton observations. We estimate the lower limit of the mass of the black hole >6 M , but with proper parameters taking into account different effects, the best estimate becomes 12 M . Our analysis favours the hypothesis that M 33 X-8 is a stellar mass black hole candidate, in agreement with the findings of other authors. In addition, we propose a different model where the high luminosity of the source is likely to be due to orientation effects of the accretion disc and anisotropies in the Comptonized emission.

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“…These findings suggest the presence of previously unknown highly ionized, massive and fast outflows from the innermost regions of radio-quiet AGNs, possibly connected with accretion disk winds/ejecta. Detailed theoretical studies of accretion disk winds in AGNs showed that the inner regions of the outflowing material can be highly ionized by the intense nuclear radiation and can have large outflow velocities (e.g., King & Pounds 2003;Proga & Kallman 2004;Everett & Ballantyne 2004;Ohsuga et al 2009;King 2010). Therefore, when the observer line of sight intercepts the flow, considerable absorption features from highly ionized species can be imprinted in the X-ray spectrum.…”

Section: Introductionmentioning

confidence: 99%

Evidence for ultra-fast outflows in radio-quiet AGNs

Tombesi

Cappi²,

Reeves

et al. 2010

A&A

617

749

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Context. Blue-shifted Fe K absorption lines have been detected in recent years between 7 and 10 keV in the X-ray spectra of several radio-quiet AGNs. The derived blue-shifted velocities of the lines can often reach mildly relativistic values, up to 0.2-0.4c. These findings are important because they suggest the presence of a previously unknown massive and highly ionized absorbing material outflowing from their nuclei, possibly connected with accretion disk winds/outflows. Aims. The scope of the present work is to statistically quantify the parameters and incidence of the blue-shifted Fe K absorption lines through a uniform analysis on a large sample of radio-quiet AGNs. This allows us to assess their global detection significance and to overcome any possible publication bias. Methods. We performed a blind search for narrow absorption features at energies greater than 6.4 keV in a sample of 42 radio-quiet AGNs observed with XMM-Newton. A simple uniform model composed by an absorbed power-law plus Gaussian emission and absorption lines provided a good fit for all the data sets. We derived the absorption lines parameters and calculated their detailed detection significance making use of the classical F-test and extensive Monte Carlo simulations. Results. We detect 36 narrow absorption lines on a total of 101 XMM-Newton EPIC pn observations. The number of absorption lines at rest-frame energies higher than 7 keV is 22. Their global probability to be generated by random fluctuations is very low, less than 3 × 10 −8 , and their detection have been independently confirmed by a spectral analysis of the MOS data, with associated random probability <10 −7 . We identify the lines as Fe XXV and Fe XXVI K-shell resonant absorption. They are systematically blue-shifted, with a velocity distribution ranging from zero up to ∼0.3c, with a peak and mean value at ∼0.1c. We detect variability of the lines on both EWs and blue-shifted velocities among different XMM-Newton observations even on time-scales as short as a few days, possibly suggesting somewhat compact absorbers. Moreover, we find no significant correlation between the cosmological red-shifts of the sources and the lines blue-shifted velocities, ruling out any systematic contamination by local absorption. If we define ultra-fast outflows (UFOs) those highly ionized absorbers with outflow velocities higher than 10 4 km s −1 , then the majority of the lines are consistent with being associated to UFOs and the fraction of objects with detected UFOs in the whole sample is at least ∼35%. This fraction is similar for type 1 and type 2 sources. The global covering fraction of the absorbers is consequently estimated to be in the range C ∼ 0.4−0.6, thereby implying large opening angles. Conclusions. From our systematic X-ray spectral analysis on a large sample of radio-quiet AGNs we have been able to clearly assess the global veracity of the blue-shifted Fe K absorption lines at E > 7 keV and to overcome their publication bias. These lines indicate that UFOs are a rather ...

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Black hole winds

Cited by 364 publications

References 7 publications

X-ray evidence for a mildly relativistic and variable outflow in the luminous Seyfert 1 galaxy Mrk 509

X-ray evidence for a mildly relativistic and variable outflow in the luminous Seyfert 1 galaxy Mrk 509

XMM–Newtonobservations of the ultraluminous nuclear X-ray source in M 33

Evidence for ultra-fast outflows in radio-quiet AGNs

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