Low- and High-<i>z</i>Highly Accreting Quasars in the 4D Eigenvector 1 Context

Marziani, Paola; Sulentic, J. W.; Negrete, C. A.; Dultzin, D.; D’Onofrio, M.; Olmo, A. del; Martínez-Aldama, Mary Loli

doi:10.1080/21672857.2014.11519739

Cited by 7 publications

(7 citation statements)

References 116 publications

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“…The photometric radius of the BLR cτ BLR increases with the width of the BEL's profiles (Figure 3), except for the case of Arp 102B. This is in accordance with the general picture of the central engine, as it appears that in objects with lower accretion rate (L/L edd ), those with larger line widths (Marziani et al, 2014) the BLR is larger. Arp 102B though remains a mystery, as here some other geometry, apart from the obvious accretion disk geometry that is usually used to explain the double-peaked line profiles, may be considered (see Popović et al, 2014).…”

Section: Discussionsupporting

confidence: 82%

Line Shape Variability in a Sample of AGN with Broad Lines

et al. 2015

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The spectral variability of active galactic nuclei (AGN) is one of their key features that enables us to study in more details the structure of AGN emitting regions. Especially, the broad line profiles, that vary both in flux and shape, give us invaluable information about the kinematics and geometry of the broad line region (BLR) where these lines are originating from.We give here a comparative review of the line shape variability in a sample of five type 1 AGN, those with broad emission lines in their spectra, of the data obtained from the international long-term optical monitoring campaign coordinated by the Special Astrophysical Observatory of the Russian Academy of Science. The main aim of this campaign is to study the physics and kinematics of the BLR on a uniform data set, focusing on the problems of the photoionization heating of the BLR and its geometry, where in this paper we give for a first time a comparative analysis of the variabilty of five type 1 AGN, discussing their complex BLR physics and geometry in the framework of the estimates of the supermassive black hole mass in AGN.

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Section: Discussionsupporting

confidence: 82%

Line Shape Variability in a Sample of AGN with Broad Lines

et al. 2015

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“…This line of study was further pursued by several authors (Dultzin-Hacyan & Ruano 1996;Sulentic et al 2000;Boroson 2002;Kuraszkiewicz et al 2009). In recent studies, instead of a full EV1, a reduced EV1 was used, with four elements (Sulentic et al 2009;Marziani et al 2014;Sulentic & Marziani 2015). The optical plane version was just based on two quantities: the ratio of the equivalent width (EW) of Fe II complex, measured in the 4434 -4684Å wavelength range to Hβ range, R Fe , and the Full Width at Half Maximum (FWHM) of Hβ (Shen & Ho 2014).…”

Section: Introductionmentioning

confidence: 99%

Modeling of the Quasar Main Sequence in the Optical Plane

Panda

Czerny

Adhikari

et al. 2018

ApJ

114

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The concept of the quasar main sequence is very attractive since it stresses correlations between various parameters and implies the underlying simplicity. In the optical plane defined by the width of the Hβ line and the ratio of the equivalent width of the Fe II to Hβ observed objects form a characteristic pattern. In this paper, we use a physically motivated model to explain the distribution of quasars in the optical plane. Continuum is modelled as an accretion disk with a hard X-ray power law uniquely tight to the disk at the basis of observational scaling, and the Broad Line Region distance is determined also from observational scaling. We perform the computations of the FeII and Hβ line production with the code CLOUDY. We have only six free parameters for an individual source: maximum temperature of the accretion disk, Eddington ratio, cloud density, cloud column density, microturbulence, and iron abundance, and only the last four remain as global parameters in our modelling of the whole sequence. Our theoretically computed points cover well the optical plane part populated with the observed quasars, particularly if we allow for super-Solar abundance of heavy elements. Explanation of the exceptionally strong Fe II emitter requires a stronger contribution from the dark sides of the clouds. Analyzing the way how our model covers the optical plane we conclude that there is no single simple driver behind the sequence, as neither the Eddington ratio nor broad band spectrum shape plays the dominant role. Also, the role of the viewing angle in providing the dispersion of the quasar main sequence is apparently not as strong as expected.

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“…The essential step was made by Boroson & Green (1992) with the use of the Principal Component Analysis (PCA). This line of research was pursued by many authors (Dultzin-Hacyan & Ruano 1996;Sulentic et al 2000;Boroson 2002;Kuraszkiewicz et al 2009;Marziani et al 2014) and has lead to the concept of the Quasar Main Sequence. In the simplest version, it can be reduced to the optical plane, when only two quantities are considered: kinematic width of the Hβ line and the ratio R FeII of the equivalent width (EW) of the Fe II emission in the 4434-4684Å range to EW of Hβ line (see e.g.…”

Section: Introductionmentioning

confidence: 99%

CLOUDY View of the Warm Corona

Panda

Czerny

Done

et al. 2019

ApJ

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Bright active galaxies show a range of properties but many of these properties are correlated which has led to the concept of the Quasar Main Sequence. We test whether our current understanding of the quasar structure allows to reproduce the pattern observed in the optical plane formed by the kinematic line width of Hβ and the relative importance of the Fe II optical emission. We performed simulations of the Hβ and Fe II production using the code CLOUDY and well justified assumptions about the broad band spectra, distance of the emission line region, and the cloud properties. We show that the presence of the warm corona is an important element of the broad band spectrum which decreases the dependence of the relative Fe II emissivity on the Eddington ratio, and allows to reproduce the rare cases of the particularly strong Fe II emitters. Results are sensitive to the adopted cloud distance, and strong Fe II emission can be obtain either by adopting strongly super-solar metallicity, or much shorter distance than traditionally obtained from reverberation mapping. We modeled in a similar way the UV plane defined by the Mg II line and Fe II UV pseudo-continuum, but here our approach is less successful, in general overproducing the Fe II strength. We found that the Fe II optical and UV emissivity depend in a different way on the turbulent velocity and metallicity, and the best extension of the model in order to cover both planes is to allow very large turbulent velocities in the Broad Line Region clouds.

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Low- and High-zHighly Accreting Quasars in the 4D Eigenvector 1 Context

Cited by 7 publications

References 116 publications

Line Shape Variability in a Sample of AGN with Broad Lines

Line Shape Variability in a Sample of AGN with Broad Lines

Modeling of the Quasar Main Sequence in the Optical Plane

CLOUDY View of the Warm Corona

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