Broad-line Balmer decrements in blue active galactic nuclei

Dong, Xiao-Bo; Wang, Tinggui; Wang, Jianguo; Yuan, Weimin; Zhou, Hongyan; Dai, Haifeng; Zhang, Kai

doi:10.1111/j.1365-2966.2007.12560.x

Cited by 167 publications

(142 citation statements)

References 95 publications

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“…The average value of BLR Balmer ratio of 3.06 obtained by Dong et al (2008) for a large, homogeneous sample of ∼500 low-redshift type 1 AGN with minimal dust extinction effects, suggest that we can assume a ratio of 3.1 also for the BLR. We assumed the same ratio also for the outflow components.…”

Section: Estimates Of Extinctionmentioning

confidence: 99%

Galaxy-wide outflows inz~ 1.5 luminous obscured quasars revealed through near-IR slit-resolved spectroscopy

Perna

Brusa

Cresci

et al. 2015

A&A

121

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Aims. The co-evolution of galaxies and supermassive black holes (SMBHs) requires that some sort of feedback mechanism is operating during the active galactic nuclei (AGN) phases. AGN driven winds are the most likely candidates for such feedback mechanism, but direct observational evidence of their existence and of their effects on the host galaxies are still scarce and their physical origin is still hotly debated. Methods. X-Shooter observations of a sample of X-ray selected, obscured quasars at z ∼ 1.5, selected on the basis of their observed red colors and X-ray-to-optical flux ratio, have shown the presence of outflowing ionized gas identified by broad [OIII] emission lines in 6 out of 8 objects, confirming the efficiency of the selection criteria. Here we present slit-resolved spectroscopy for the two brightest sources, XID2028 and XID5321, to study the complex emission and absorption line kinematics. Results. We detect outflow extended out to ∼10 kpc from the central black hole, both as blueshifted and redshifted emission. Interestingly, we also detect kpc scale outflows in the [OII] emission lines and in the neutral gas component, traced by the sodium D and magnesium absorption lines, confirming that a substantial amount of the outflowing mass is in the form of neutral gas. Conclusions. The measured gas velocities and the outflow kinetic powers, inferred under reasonable assumptions on the geometry and physical properties of these two systems, favor an AGN origin for the observed winds.

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Section: Estimates Of Extinctionmentioning

confidence: 99%

Galaxy-wide outflows inz~ 1.5 luminous obscured quasars revealed through near-IR slit-resolved spectroscopy

Perna

Brusa

Cresci

et al. 2015

A&A

121

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“…Recently, the large sample statistics suggests that the intrinsic value of broad-line Hα/Hβ is 3.06 with a standard deviation of 0.03 dex (Dong et al 2008). Gaskell & Ferland (1984) presented the relative strengths of Pα and Hβ for low-density gas was very close to the Case-B value, 0.34, here it was assumed to be applicable for the broad emission lines.…”

Section: Balmer and Paschen Emission Linesmentioning

confidence: 99%

Reddening and He i^∗ λ10830 Absorption Lines in Three Narrow-line Seyfert 1 Galaxies

Zhang

Zhou

Shi

et al. 2017

ApJ

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We report the detection of heavy reddening and the He I* λ10830 absorption lines at the AGNs' redshift in three Narrow-line Seyfert 1 galaxies: SDSS J091848.61+211717.0, SDSS J111354.66+124439.0, and SDSS J122749.13+321458.9. They exhibit very red optical to nearinfrared colors, narrow Balmer/Paschen broad emission lines and He I* λ10830 absorption lines. The ultraviolet-optical-infrared nucleus continua are reddened by the SMC extinction law of E(B − V ) ∼ 0.74, 1.17, and 1.24 mag for three objects, which are highly consistent with the values obtained from the broad-line Balmer decrements, but larger than those of narrow emission lines. The reddening analysis suggests the extinction dust simultaneously obscure the accretion disk, the broad emission line region, and the hot dust from the inner edge of the torus. It is possible that the dust obscuring the AGN structures are the dusty torus itself. Furthermore, the Cloudy analysis of the He I* λ10830 absorption lines propose the distance of the absorption materials to be the extend scale of the torus. That greatly increases probabilities of the obscure and absorption materials being the dusty torus.

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“…We find that, for our Type 1 AGNs, our derived optical extinctions result mostly in intrinsic ratios of 1-7 with most objects scattered around the Case B value of 3.1. Dong et al (2008) Figure 3. Comparison between the X-ray absorbing column density (N H ) and the optical extinction measured using the broad Hα-to-X-ray relationship.…”

Section: Comparison With Hα/hβ Ratiosmentioning

confidence: 99%

BAT AGN Spectroscopic Survey. VIII. Type 1 AGN with Massive Absorbing Columns

Shimizu

Davies

Koss

et al. 2018

ApJ

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractWe explore the relationship between X-ray absorption and optical obscuration within the BAT AGN Spectroscopic Survey (BASS), which has been collecting and analyzing the optical and X-ray spectra for 641 hard X-ray selected (E>14keV) active galactic nuclei (AGNs). We use the deviation from a linear broad Hα-to-X-ray relationship as an estimate of the maximum optical obscuration toward the broad line region (BLR) and compare the A V to the hydrogen column densities (N H ) found through systematic modeling of their X-ray spectra. We find that the inferred columns implied by A V toward the BLR are often orders of magnitude less than the columns measured toward the X-ray emitting region, indicating a small-scale origin for the X-ray absorbing gas. After removing 30% of Sy 1.9s that potentially have been misclassified due to outflows, we find that 86% (164/190) of the Type 1 population (Sy 1-1.9) are X-ray unabsorbed as expected based on a single obscuring structure. However, 14% (26/190), of which 70% (18/26) are classified as Sy 1.9, are X-ray absorbed, suggesting that the BLR itself is providing extra obscuration toward the X-ray corona. The fraction of X-ray absorbed Type 1 AGNs remains relatively constant with AGN luminosity and Eddington ratio, indicating a stable BLR covering fraction.

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Broad-line Balmer decrements in blue active galactic nuclei

Cited by 167 publications

References 95 publications

Galaxy-wide outflows inz~ 1.5 luminous obscured quasars revealed through near-IR slit-resolved spectroscopy

Galaxy-wide outflows inz~ 1.5 luminous obscured quasars revealed through near-IR slit-resolved spectroscopy

Reddening and He i^∗ λ10830 Absorption Lines in Three Narrow-line Seyfert 1 Galaxies

BAT AGN Spectroscopic Survey. VIII. Type 1 AGN with Massive Absorbing Columns

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Broad-line Balmer decrements in blue active galactic nuclei

Cited by 167 publications

References 95 publications

Galaxy-wide outflows inz~ 1.5 luminous obscured quasars revealed through near-IR slit-resolved spectroscopy

Galaxy-wide outflows inz~ 1.5 luminous obscured quasars revealed through near-IR slit-resolved spectroscopy

Reddening and He i∗ λ10830 Absorption Lines in Three Narrow-line Seyfert 1 Galaxies

BAT AGN Spectroscopic Survey. VIII. Type 1 AGN with Massive Absorbing Columns

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Reddening and He i^∗ λ10830 Absorption Lines in Three Narrow-line Seyfert 1 Galaxies