An analysis of the narrow line profiles in Seyfert 2 galaxies

Robertis, M. M. De; Osterbrock, Donald E.

doi:10.1086/163939

Cited by 93 publications

(74 citation statements)

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“…Spectral transitions with higher critical densities generally exhibit broader line proÐles. There are also cases where the observed widths are higher for transitions in ions with higher ionization potential, which corresponds to a scenario with b \ 2 (e.g., Pelat, Alloin, & Fosbury 1981 ;Filippenko & Halpern 1994 ;De Robertis & Osterbrock 1984). According to De Robertis & Osterbrock (1986), values of b lie between 0 and 2, while more Seyfert 2 galaxies have b closer to 2.…”

Section: Discussionmentioning

confidence: 96%

The Physical Conditions of the X‐Ray Emission Line Regions in the Circinus Galaxy

Šako¹,

Kahn²,

Paerels³

et al. 2000

ApJ

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We present a detailed X-ray spectral analysis of the Circinus galaxy using archival data obtained with the ASCA satellite. The spectrum shows numerous emission lines in the soft X-ray band from highly ionized ions, as well as Compton reÑection and Ñuorescent lines from neutral or near-neutral matter. We analyze the spectrum in the context of a self-consistent recombination cascade model and Ðnd that a nearly Ñat di †erential emission measure (DEM) distribution in ionization parameter Ðts the data. For a Ðxed solid angle distribution of matter surrounding a point source, this corresponds to a run of electron density of the form n(r) D r~3@2, which is suggestive of Bondi accretion onto a central compact mass. Using this density proÐle and comparing the resulting emission spectra with the ASCA data, the size of the X-ray emission line region is estimated to be kpc. We also show that the derived density as a [1 function of radius is compatible with the X-ray recombination line emission region being the conÐning medium of the coronal line regions.

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Section: Discussionmentioning

confidence: 96%

The Physical Conditions of the X‐Ray Emission Line Regions in the Circinus Galaxy

Šako¹,

Kahn²,

Paerels³

et al. 2000

ApJ

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“…The four extremely red quasars with median log(νL ν [13.5µm]/L[OIII]) = 3.18 lie at least an order of magnitude above the correlation for type 2 quasars and half an order of magnitude above the correlation for type 1s, suggesting that [OIII] is suppressed by extinction by a factor of 3−10 (we offer this comparison with a caution that the extremely red quasar sample is infraredselected and thus may have an infrared-to-[OIII] ratio biased somewhat high). Furthermore, the strong effect of dust extinction on [OIII] is also clear from the shape of the emission lines: the large overall blueshift of [OIII] is likely produced due to the extinction of the redshifted part of the outflow by the observer-facing (blue-shifted) part of the outflow (Heckman et al 1981;De Robertis & Osterbrock 1984;Whittle 1985a;Wilson & Heckman 1985;Crenshaw et al 2010). Finally, the REW[OIII] values of extremely red quasars (intermediate between those of type 1 and type 2 quasars) also support the notion of dust extinction of the [OIII]-emitting region.…”

Section: 1mentioning

confidence: 99%

Discovery of extreme [O iii] λ5007 Å outflows in high-redshift red quasars

Zakamska

Hamann

Pâris

et al. 2016

Mon. Not. R. Astron. Soc.

210

275

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Black hole feedback is now a standard component of galaxy formation models. These models predict that the impact of black hole activity on its host galaxy likely peaked at z = 2−3, the epoch of strongest star formation activity and black hole accretion activity in the Universe. We used XShooter on the Very Large Telescope to measure rest-frame optical spectra of four z ∼ 2.5 extremely red quasars with infrared luminosities ∼ 10 47 erg s −1 . We present the discovery of very broad (full width at half max= 2600 − 5000 km s −1 ), strongly blue-shifted (by up to 1500 km s −1 ) [OIII]λ5007Å emission lines in these objects. In a large sample of type 2 and red quasars, [OIII] kinematics are positively correlated with infrared luminosity, and the four objects in our sample are on the extreme end both in [OIII] kinematics and infrared luminosity. We estimate that at least 3% of the bolometric luminosity in these objects is being converted into the kinetic power of the observed wind. Photo-ionization estimates suggest that the [OIII] emission might be extended on a few kpc scales, which would suggest that the extreme outflow is affecting the entire host galaxy of the quasar. These sources may be the signposts of the most extreme form of quasar feedback at the peak epoch of galaxy formation, and may represent an active "blow-out" phase of quasar evolution.

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“…We note that while we span a narrow range in luminosity, we actually span a wide range in σ * , suggesting that the lack of correlation is a generic property of luminous obscured AGNs, and may well be a generic property of all AGNs at such high luminosities. We try to salvage the correlation by relying on lines with lower ionization potential, since many studies have found systematic trends between line shape and the critical density or ionization potential of the lines (e.g., Pelat et al 1981;Filippenko & Halpern 1984;Filippenko 1985;De Robertis & Osterbrock 1986). Generically speaking, the high-ionization and/or highcritical density lines originate from closer to the BH and are thus typically broader, making low-ionization lines a better choice as proxies to σ * (e.g., Greene & Ho 2005a;Komossa & Xu 2007).…”

Section: Comparison Of Stellar and Gaseous Kinematicsmentioning

confidence: 99%

The Growth of Black Holes: Insights From Obscured Active Galaxies

Greene

Zakamska

Liu

et al. 2009

ApJ

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Obscured or narrow-line active galaxies offer an unobstructed view of the quasar environment in the presence of a luminous and vigorously accreting black hole (BH). We exploit the large new sample of optically selected luminous narrow-line active galaxies from the Sloan Digital Sky Survey at redshifts 0.1 < z < 0.45, in conjunction with follow-up observations with the Low Dispersion Survey Spectrograph (LDSS3) at Magellan, to study the distributions of BH mass and host galaxy properties in these extreme objects. We find a narrow range in BH mass ( log M BH /M = 8.0 ± 0.7) and Eddington ratio ( log L bol /L Edd = −0.7 ± 0.7) for the sample as a whole, surprisingly similar to comparable broad-line systems. In contrast, we infer a wide range in star formation properties and host morphologies for the sample, from disk-dominated to elliptical galaxies. Nearly one-quarter have highly disturbed morphologies indicative of ongoing mergers. Unlike the BHs, which are apparently experiencing significant growth, the galaxies appear to have formed the bulk of their stars at a previous epoch. On the other hand, it is clear from the lack of correlation between gaseous and stellar velocity dispersions in these systems that the host galaxy interstellar medium is far from being in virial equilibrium with the stars. While our findings cast strong doubt on the reliability of substituting gas for stellar dispersions in high luminosity active galaxies, they do provide direct evidence that luminous accreting BHs influence their surroundings on a galaxy-wide scale.

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An analysis of the narrow line profiles in Seyfert 2 galaxies

Cited by 93 publications

References 0 publications

The Physical Conditions of the X‐Ray Emission Line Regions in the Circinus Galaxy

The Physical Conditions of the X‐Ray Emission Line Regions in the Circinus Galaxy

Discovery of extreme [O iii] λ5007 Å outflows in high-redshift red quasars

The Growth of Black Holes: Insights From Obscured Active Galaxies

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