OPTICAL SPECTRAL PROPERTIES OF<i>SWIFT</i>BURST ALERT TELESCOPE HARD X-RAY-SELECTED ACTIVE GALACTIC NUCLEI SOURCES

Winter, L. M.; Lewis, Karen T.; Koss, Michael; Veilleux, Sylvain; Keeney, Brian A.; Mushotzky, R. F.

doi:10.1088/0004-637x/710/1/503

Cited by 97 publications

(109 citation statements)

References 62 publications

(111 reference statements)

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“…This is consistent with the idea that the [O iii] emission from some AGNs is low (see also Winter et al 2010 for evidence of this in the Swift BAT sample). This dispersion in the amount of [O iii] light produced by an AGN also implies that we will not be able to tell the strength of the AGN relative to the star formation as we move along the wing, as some modelers have proposed (e.g., Kewley et al 2006).…”

Section: Discussionsupporting

confidence: 90%

“…Since two L X > 10 43 erg s −1 AGNs lie in the transition region and two 5 × 10 42 erg s −1 < L X < 10 43 erg s −1 AGNs lie below the Kauffmann et al (2003) line, it is clear that the optical diagnostic diagram is not able to classify all of the X-rayselected non-BLAGNs with line ratio measurements as AGNs (see also Winter et al 2010 for evidence of this in the Swift BAT sample). Given that we are working from a high X-ray luminosity sample, this seems rather surprising.…”

Section: Emission-line Ratio Diagnostic Diagramsmentioning

confidence: 99%

“…Since the narrow emission-line region lies outside of the dusty torus, the emission lines should not suffer from obscuration by that high column density material (though they may be affected by dust within the host galaxy). Although there is some evidence that the [O iii] luminosity is a good measure of AGN activity (e.g., Mulchaey et al 1994), and, indeed, many researchers have assumed it to be so in their analyses (e.g., Alonso-Herrero et al 1997;Hao et al 2005;Netzer et al 2006;Bongiorno et al 2010), recent work has called this conclusion into question (e.g., Cocchia et al 2007;Meléndez et al 2008;Diamond-Stanic et al 2009;La Massa et al 2009;Winter et al 2010).…”

Section: Introductionmentioning

confidence: 99%

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The Optx Project. Iv. How Reliable Is [O Iii] as a Measure of Agn Activity?

Trouille

Barger

2010

ApJ

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We compare optical and hard X-ray identifications of active galactic nuclei (AGNs) using a uniformly selected (above a flux limit of f 2-8 keV = 3.5 × 10 −15 erg cm −2 s −1 ) and highly optically spectroscopically complete (>80% for f 2-8 keV > 10 −14 erg cm −2 s −1 and >60% below) 2-8 keV sample observed in three Chandra fields (CLANS, CLASXS, and the CDF-N). We find that empirical emission-line ratio diagnostic diagrams misidentify 50% of the X-ray-selected AGNs that can be put on these diagrams as star formers. We confirm that there is a large (two orders of magnitude) dispersion in the ratio of the [O iii]λ5007 (hereafter [O iii]) to hard X-ray luminosities for the non-broad-line AGNs, even after applying reddening corrections to the [O iii] luminosities. We find that the dispersion is similar for the broad-line AGNs, where there is not expected to be much X-ray absorption from an obscuring torus around the AGN nor much obscuration from the galaxy along the line of sight if the AGN is aligned with the galaxy. We postulate that the X-ray-selected AGNs that are misidentified by the diagnostic diagrams have low [O iii] luminosities due to the complexity of the structure of the narrow-line region, which causes many ionizing photons from the AGN not to be absorbed. This would mean that the [O iii] luminosity can only be used to predict the X-ray luminosity to within a factor of ∼3 (1σ ). Despite selection effects, we show that the shapes and normalizations of the [O iii] and transformed hard X-ray luminosity functions show reasonable agreement, suggesting that the [O iii] samples are not finding substantially more AGNs at low redshifts than hard X-ray samples.

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Section: Discussionsupporting

confidence: 90%

Section: Emission-line Ratio Diagnostic Diagramsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Optx Project. Iv. How Reliable Is [O Iii] as a Measure of Agn Activity?

Trouille

Barger

2010

ApJ

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“…Indeed, this AGN catalog is one of the most complete to date (see e.g. Winter et al 2009Winter et al , 2010Weaver et al 2010;Ichikawa et al 2012;Ueda et al 2015).…”

Section: Sample Selectionmentioning

confidence: 99%

The nuclear and extended mid-infrared emission of Seyfert galaxies

García-Bernete¹,

Almeida²,

Acosta–Pulido³

et al. 2016

Mon. Not. R. Astron. Soc.

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We present subarcsecond resolution mid-infrared (MIR) images obtained with 8-10 m-class ground-based telescopes of a complete volume-limited (D L <40 Mpc) sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog. We use those MIR images to study the nuclear and circumnuclear emission of the galaxies. Using different methods to classify the MIR morphologies on scales of ∼400 pc, we find that the majority of the galaxies (75-83%) are extended or possibly extended and 17-25% are point-like. This extended emission is compact and it has low surface brightness compared with the nuclear emission, and it represents, on average, ∼30% of the total MIR emission of the galaxies in the sample. We find that the galaxies whose circumnuclear MIR emission is dominated by star formation show more extended emission (650±700 pc) than AGN-dominated systems (300±100 pc). In general, the galaxies with point-like MIR morphologies are face-on or moderately inclined (b/a∼0.4-1.0), and we do not find significant differences between the morphologies of Sy1 and Sy2. We used the nuclear and circumnuclear fluxes to investigate their correlation with different AGN and SF activity indicators. We find that the nuclear MIR emission (the inner ∼70 pc) is strongly correlated with the X-ray emission (the harder the X-rays the better the correlation) and with the [O IV] λ25.89 µm emission line, indicating that it is AGN-dominated. We find the same results, although with more scatter, for the circumnuclear emission, which indicates that the AGN dominates the MIR emission in the inner ∼400 pc of the galaxies, with some contribution from star formation.

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“…Thus, we added to the fit a Gaussian profiled emission line. We left the line centroid free to vary among the nominal wavelengths of the O vii triplet and we used the width of the broad H α line given in Winter et al (2010) to set the fitting range for the width Table 2. Best fit parameters and errors for the final best fit model.…”

Section: Emission Linesmentioning

confidence: 99%

The warm absorber in the radio-loud quasar 4C +74.26

Gesu

Costantini

2016

A&A

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Outflows of photoionized gas are commonly detected in the X-ray spectra of Seyfert 1 galaxies. However, the evidence for this phenomenon in broad line radio galaxies, which are analogous to Seyfert 1 galaxies in the radio-loud regime, has so far been scarce. Here, we present the analysis of the X-ray absorption in the radio-loud quasar 4C +74.26. With the aim of characterizing the kinetic and the ionization conditions of the absorbing material, we fitted jointly the XMM-Newton Reflection Grating Spectrometer (RGS) and the Chandra High Energy Transmission Grating Spectrometer (HETGS) spectra, which were taken 4 months apart. The intrinsic continuum flux did not vary significantly during this time lapse. The spectrum shows the absorption signatures (e.g., Fe-UTA, O vii, and Ne vii-Ne x) of a photoionized gas outflow ( N H ∼ 3.5 × 10 21 cm −2 , log ξ ∼ 2.6, v out ∼ 3600 km s −1 ) located at the redshift of source. We estimate that the gas is located outside the broad line region but within the boundaries of the putative torus. This ionized absorber is consistent with the X-ray counterpart of a polar scattering outflow reported in the optical band for this source. The kinetic luminosity carried by the outflow is insufficient to produce a significant feedback is this quasar. Finally, we show that the heavy soft X-ray absorption that was noticed in the past for this source arises mostly in the Galactic ISM.

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OPTICAL SPECTRAL PROPERTIES OFSWIFTBURST ALERT TELESCOPE HARD X-RAY-SELECTED ACTIVE GALACTIC NUCLEI SOURCES

Cited by 97 publications

References 62 publications

The Optx Project. Iv. How Reliable Is [O Iii] as a Measure of Agn Activity?

The Optx Project. Iv. How Reliable Is [O Iii] as a Measure of Agn Activity?

The nuclear and extended mid-infrared emission of Seyfert galaxies

The warm absorber in the radio-loud quasar 4C +74.26

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