Average Quasar Spectra in the Context of Eigenvector 1

Sulentic, J. W.; Marziani, Paola; Zamanov, R.; Bachev, R.; Calvani, M.; Dultzin‐Hacyan, D.

doi:10.1086/339594

Cited by 172 publications

(290 citation statements)

References 15 publications

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“…Variants of E1 were later found in several studies (e.g. Marziani et al 1996;Boroson 2002;Grupe 2004;Kuraszkiewicz et al 2002;Sulentic et al 2000bSulentic et al , 2002Yip et al 2004;Kovačević et al 2010;Kruczek et al 2011;Tang et al 2012;Wang et al 2006).…”

Section: Introductionmentioning

confidence: 82%

“…The higher dimensionality involves parameters that are observationally independent and that correspond to different physical processes (see the reviews by Sulentic et al 2000a and for more detailed discussions). Quasars occupy a well defined sequence in the "optical plane" of 4DE1 defined by the FWHM of the Hβ broad component and by the intensity ratio between Feiiλ4570 and Hβ, R FeII = I(Feiiλ4570)/I(Hβ) (Boroson & Green 1992;Sulentic et al 2002). The 4DE1 optical plane therefore offers a tool that allows for defining and identifying quasar populations or spectral types.…”

Section: Introductionmentioning

confidence: 99%

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Is MgIIλ2800 a reliable virial broadening estimator for quasars?

Marziani

Sulentic

Plauchu-Frayn

et al. 2013

A&A

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156

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Context. Broad Mgiiλ2800 and Hβ lines have emerged as the most reliable virial estimators of the black hole mass in quasars. Which is more reliable? Part of the challenge centers on comparing Mgiiλ2800 and Hβ line profiles in order to improve the ±1 dex M BH uncertainties inherent in single-epoch FWHM measures from noisy spectra. Aims. We compare Mgiiλ2800 and Hβ profile measures in the same sources and especially FWHM measures that provide the virial broadening estimator. Methods. We identify 680 bright Sloan Digital Sky Survey Data Release 7 quasars with spectra showing both Mgiiλ2800 and Hβ lines at redshift 0.4 ≤ z ≤ 0.75. The S/N of these spectra are high enough to allow binning in the "four-dimensional (4D) eigenvector 1" optical plane and construction of high S/N composite spectra. Results. We confirm that Mgiiλ2800 shows a profile that is ≈20% narrower as suggested in some previous studies. FWHM measures for Population B sources (i.e., with FWHM of Hβ larger than 4000 km s −1 ) are uncertain because they show complex profiles with at least two broad-line components involving a nearly unshifted broad and redshifted very-broad component. Only the broad component is likely to be a valid virial estimator. If Hβ and Mgiiλ2800 are not corrected for the very broad component then black hole mass M BH values for Population B sources will be systematically overestimated by up to Δ logM BH ≈ 0.3−0.4 dex. We suggest a simple correction that can be applied to the majority of sources. Mgiiλ2800 is the safer virial estimator for Population B sources because the centroid shifts with respect to rest frame are lower than for Hβ. In the broad and very broad component profile interpretation, this is a consequence of the lower very broad to broad component intensity ratio for Mgiiλ2800. Eigenvector-based studies show that effective discrimination of black hole mass and Eddington ratio at fixed redshift is not achieved via luminosity binning but rather by binning in a "4D eigenvector 1" context that reflects different broad line region geometry/kinematics probably driven by the Eddington ratio.

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Section: Introductionmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Is MgIIλ2800 a reliable virial broadening estimator for quasars?

Marziani

Sulentic

Plauchu-Frayn

et al. 2013

A&A

Self Cite

156

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“…The best low-z composites come from Bachev et al (2004). This sample was large enough to permit constructing composite spectra for each of the five most populated 4DE1 bins (Sulentic et al 2002). The bin composites were then combined to produce two higher S/N composites for populations A and B. Low-z population A and B composites shown in the bottom panel of Fig.…”

Section: Comparing Population a And B Uv Spectra At High And Low Redsmentioning

confidence: 99%

“…We do not report M BH and L/L Edd estimates for individual sources, but follow the procedure developed in Sulentic et al (2002) and Marziani et al (2009), which involves producing high S/N composite spectra in the 4DE1 context. This was previously performed for our low-z control sample (Bachev et al 2004), where composites for the five most populated bins were generated.…”

Section: Bh and L/l Edd At High And Low Zmentioning

confidence: 99%

GTC spectra ofz≈ 2.3 quasars: comparison with local luminosity analogs

Sulentic¹,

Marziani²,

Olmo³

et al. 2014

A&A

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Context. The advent of 8−10 m class telescopes for the first time makes it possible to compare in detail quasars with similar luminosity and very different redshifts. Aims. We conducted a search for z-dependent gradients in line-emission diagnostics and derived physical properties by comparing, in a narrow bolometric luminosity range (log L ∼ 46.1± 0.4 [erg s −1 ]), some of the most luminous local z < 0.6 quasars with some of the lowest luminosity sources yet found at redshift z = 2.1−2.5. Methods. Moderate signal-to-noise ratio spectra for 22 high-redshift sources were obtained with the 10.4 m Gran Telescopio Canarias (GTC), for which the HST (largely the Faint Object Spectrograph) archive provides a low-redshift control sample. We compared the spectra in the context of the 4D Eigenvector 1 formalism, meaning that we divided both source samples into highly accreting population A and population B sources accreting at a lower rate. Results. Civλ1549, the strongest and most reliable diagnostic line, shows very similar properties at both redshifts, which confirms the Civλ1549 profile differences at high redshift between populations A and B, which are well established in local quasars. The Civλ1549 blueshift that appears quasi-ubiquitous in higher L sources is found in only half (population A) of the quasars observed in the two samples. A Civλ1549 evolutionary Baldwin effect is certainly disfavored. We find evidence for lower metallicity in the GTC sample that may point toward a gradient with z. No evidence for a gradient in M BH or L/L Edd is found. Conclusions. Spectroscopic differences established at low z are also present in much higher redshift quasars. Our results on the Civλ1549 blueshift suggest that it depends both on source luminosity and L/L Edd . Given that our samples involve sources with very similar luminosity, the evidence for a systematic metallicity decrease, if real, points toward an evolutionary effect. Our samples are not large enough to effectively constrain possible changes of M BH or L/L Edd with redshift. The two samples appear representative of a slowly evolving quasar population that is most likely present at all redshifts.

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“…Sulentic et al (2000; expanded the E1 trends into a 4-dimensional space involving optical, UV and X-ray measures. They also defined spectral types along a sequence occupied by AGN in an optical plane involving Feii and FWHM Hβ parameters (Sulentic et al 2002). Objects at extreme ends of the E1 sequence are very different at almost all wavelengths and median spectra computed in spectral bins within this plane emphasize systematic changes in broad line properties (Sulentic et al 2002(Sulentic et al , 2007.…”

Section: Quasar Systematicsmentioning

confidence: 99%

A New Method to Obtain the Broad Line Region Size of High Redshift Quasars

Negrete¹,

Dultzin²,

Marziani³

et al. 2014

ApJ

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We present high S/N UV spectra for eight quasars at z ∼ 3 obtained with VLT/FORS. -2 -and metallicity through the use of diagnostic maps built from cloudy simulations. The radius of the broad line region is then derived from the ionizing photon flux applying the definition of the ionization parameter. The r BLR estimate and the width of a virial component isolated in prominent UV lines yields an estimate of black hole mass. We compare our results with previous estimates obtained from the r BLR -luminosity correlation customarily employed to estimate black hole masses of high redshift quasars.

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Average Quasar Spectra in the Context of Eigenvector 1

Cited by 172 publications

References 15 publications

Is MgIIλ2800 a reliable virial broadening estimator for quasars?

Is MgIIλ2800 a reliable virial broadening estimator for quasars?

GTC spectra ofz≈ 2.3 quasars: comparison with local luminosity analogs

A New Method to Obtain the Broad Line Region Size of High Redshift Quasars

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