New insights on the accretion disk-winds connection in radio-loud AGNs from Suzaku

Tombesi, Francesco; Sambruna, R. M.; Reeves, J. N.; Braito, V.; Cappi, M.; Reynolds, Christopher S.; Mushotzky, R. F.

doi:10.1063/1.3696173

Cited by 9 publications

(18 citation statements)

References 12 publications

(13 reference statements)

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“…We can also exclude any contamination due to the EPIC pn background and calibration uncertainties and we checked that the possible presence of spectral complexities, such as reflection and warm absorption, are typically weak enough to assure a only marginal model dependency of the results. This systematic analysis on a large sample of sources allows to estimate the global detection probability of the absorption lines of >5σ and to overcame the possible publication bias claimed by Vaughan & Uttley (2008). Moreover, we checked that the results are consistent using also the MOS detectors and the global random probability in that case is also low, <10 −7 .…”

Section: Significance Of the Blue-shifted Absorption Linesmentioning

confidence: 84%

“…Their ionization is high, in the interval logξ∼2.5-6 erg s −1 cm, and the associated column densities are also large, in the range N H ∼10 22 -10 24 cm −2 . The estimated location and energetics of the UFOs in the radio-quiet sample is reported in a subsequent paper, Tombesi et al (2012).…”

Section: The Radio-quiet Samplementioning

confidence: 99%

“…The recent detection of blue-shifted Fe XXV/XXVI absorption lines in the X-ray spectra of several Seyferts and quasars suggests the presence of highly ionized and mildlyrelativistic outflows in the center of these AGNs (e.g., Chartas et al 2002Chartas et al , 2003Pounds et al 2003;Dadina et al 2005;Markowitz et al 2006;Braito et al 2007;Cappi et al 2009;Reeves et al 2009;Giustini et al 2011). They are possibly directly connected with accretion disk winds/outflows and the high associated outflow rate and mechanical power suggest they might be able to provide an important contribution to the expected AGN cosmological feedback (e.g., King 2010;Tombesi et al 2012). Here we describe the systematic analysis and characterization of these so called Ultra-fast Outflows (UFOs) on a large sample of both radio-quiet and radio-loud AGNs.…”

Section: Introductionmentioning

confidence: 99%

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Evidence for ultra-fast outflows in radio-quiet AGNs

Tombesi

Cappi²,

Reeves

et al. 2010

A&A

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647

750

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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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Section: Significance Of the Blue-shifted Absorption Linesmentioning

confidence: 84%

Section: The Radio-quiet Samplementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evidence for ultra-fast outflows in radio-quiet AGNs

Tombesi

Cappi²,

Reeves

et al. 2010

A&A

Self Cite

647

750

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show abstract

“…The X-ray warm absorbers commonly seen in Seyfert galaxies (Reynolds 1997 Establishing that the kinetic power of the wind is sufficient has proven difficult: if the evidence of the wind is from blueshifted absorption lines then obtaining the covering fraction and radius of the wind requires indirect arguments. Tombesi et al (2012) estimate that the mass outflow rate exceeds 5% of the mass accretion rate and that the lower limit on the kinetic power of the outflows in individual objects ranges from 10 42.6 − 10 44.6 erg s −1 .…”

Section: Agn Windsmentioning

confidence: 99%

Observational Evidence of Active Galactic Nuclei Feedback

Fabian

2012

Annu. Rev. Astron. Astrophys.

2,463

2,070

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Radiation, winds and jets from the active nucleus of a massive galaxy can interact with its interstellar medium leading to ejection or heating of the gas. This can terminate star formation in the galaxy and stifle accretion onto the black hole. Such Active Galactic Nucleus (AGN) feedback can account for the observed proportionality between central black hole and host galaxy mass. Direct observational evidence for the radiative or quasar mode of feedback, which occurs when the AGN is very luminous, has been difficult to obtain but is accumulating from a few exceptional objects. Feedback from the kinetic or radio mode, which uses the mechanical energy of radio-emitting jets often seen when the AGN is operating at a lower level, is common in massive elliptical galaxies. This mode is well observed directly through X-ray observations of the central galaxies of cool core clusters in the form of bubbles in the hot surrounding medium. The energy flow, which is roughly continuous, heats the hot intracluster gas and reduces radiative cooling and subsequent star formation by an order of magnitude. Feedback appears to maintain a long-lived heating/cooling balance. Powerful, jetted radio outbursts may represent a further mode of energy feedback which affect the cores of groups and subclusters. New telescopes and instruments from the radio to X-ray bands will come into operation over the next few years and lead to a rapid expansion in observational data on all modes of AGN feedback.

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“…At hard X-ray band (5-10 keV), based on XMM-Newton and Suzakue observation, the blue-shifted Fe XXV and Fe XXVI absorption lines are ubiquitously detected on AGNs spectra (Tombesi et al 2010;Gofford et al 2013;. The Fe XXV and Fe XXVI lines are shifted at ∼0.03-0.3 c, with a mean value of ∼0.14c, and they are generated in the interval 10 2 -10 4 Schwarzschild radius (r s ) from the central black hole (BH) (Tombesi et al 2012). This implies that a highly ionized absorber fast moves outward from its nucleus, for 40% of AGNs.…”

Section: Introductionmentioning

confidence: 99%

Magnetohydrodynamic Winds Driven by the Line Force from the Standard Thin Disk around Supermassive Black Holes. I. The Case of Weak Magnetic Field

Yang,

Ablimit,

2021

Preprint

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The absorption lines with high blue-shifted velocities are frequently found in the ultraviolet (UV) and X-ray spectra of luminous active galactic nuclei (AGNs). This implies that the high-velocity winds/outflows are common in AGNs. In order to study the formation of high-velocity winds, especially ultra-fast outflows (UFOs), we perform two-dimensional magnetohydrodynamic (MHD) simulations. Initially, a magnetic field is set to be weaker than the gas pressure at disk surface. In our simulations, line force operates on the region like filaments, because the X-ray radiation from corona is shielded by dense gas in the inner region at some angle. The location of filaments changes with time and then the line-driven winds are in exposure to X ray and become highly ionized. Line force at UV bands does not directly drive the highly-ionized winds. In the sense of time average, the properties of high-velocity winds meet the formation condition of UFOs. Compared with line force, the function of magnetic field is negligible in directly driving winds. In the MHD model, the region around the rotational axis becomes magnetic-pressure-dominated, which prevents gases from spreading to higher latitudes and then enhances the gas column density at middle and low latitudes (20 o -70 o ). Higher column density is helpful to shield X-ray photons, which causes that line force is more effective in the MHD model than in the HD model. Higher-velocity winds with broader opening angle are produced in the MHD model.

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New insights on the accretion disk-winds connection in radio-loud AGNs from Suzaku

Cited by 9 publications

References 12 publications

Evidence for ultra-fast outflows in radio-quiet AGNs

Evidence for ultra-fast outflows in radio-quiet AGNs

Observational Evidence of Active Galactic Nuclei Feedback

Magnetohydrodynamic Winds Driven by the Line Force from the Standard Thin Disk around Supermassive Black Holes. I. The Case of Weak Magnetic Field

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