Combined Ultraviolet and Optical Spectra of 48 Low-Redshift QSOs and the Relation of the Continuum and Emission-Line Properties

Corbin, Michael R.; Boroson, Todd A.

doi:10.1086/192355

Cited by 115 publications

(145 citation statements)

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“…This potentially can be explained as an artificially large correlation owing to their small number of objects (22 compared to our 1683 QSOs) 11 . Supporting this hypothesis, in Corbin & Boroson (1996) for a larger sample of 44 QSOs, this is reduced to ρ = 0.68 for Lyα-C IV.…”

Section: Interpreting the Covariance Matrixmentioning

confidence: 81%

Lyα emission-line reconstruction for high-zQSOs

Greig

Mesinger

McGreer

et al. 2016

Mon. Not. R. Astron. Soc.

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We introduce an intrinsic Lyα emission line profile reconstruction method for high-z quasars (QSOs). This approach utilises a covariance matrix of emission line properties obtained from a large, moderate-z (2 ≤ z ≤ 2.5), high signal to noise (S/N> 15) sample of BOSS QSOs. For each QSO, we complete a Monte Carlo Markov Chain fitting of the continuum and emission line properties and perform a visual quality assessment to construct a large database of robustly fit spectra. With this dataset, we construct a covariance matrix to describe the correlations between the high ionisation emission lines Lyα, C IV, Si IV +O IV] and C III], and find it to be well approximated by an N -dimensional Gaussian distribution. This covariance matrix characterises the correlations between the line width, peak height and velocity offset from systemic while also allowing for the existence of broad and narrow line components for Lyα and C IV. We illustrate how this covariance matrix allows us to statistically characterise the intrinsic Lyα line solely from the observed spectrum redward of 1275Å. This procedure can be used to reconstruct the intrinsic Lyα line emission profile in cases where Lyα may otherwise be obscured. Applying this reconstruction method to our sample of QSOs, we recovered the Lyα line flux to within 15 per cent of the measured flux at 1205Å (1220Å) ∼ 85 (90) per cent of the time.

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Section: Interpreting the Covariance Matrixmentioning

confidence: 81%

Lyα emission-line reconstruction for high-zQSOs

Greig

Mesinger

McGreer

et al. 2016

Mon. Not. R. Astron. Soc.

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“…In contrast, Evans et al (2001) report the detection of an edge-on CO molecular disk. UV/Optical spectroscopy on this source presented by Corbin & Boroson (1996) shows that Fe ii and Mg ii are the two most conspicuous features in its spectrum. Our NIR spectrum is totally dominated by emission from the BLR, with broad permitted lines of H i, He i, O i, and Fe ii detected.…”

Section: Notes On Individual Objectsmentioning

confidence: 89%

“…A very steep radio source and the second most distant object of the sample, 3C 351 is a lobe-dominated, radioloud QSO (log R = 2.81) with moderate-strength X-ray and ultraviolet absorption by ionized gas (Brandt et al 2000). UV/optical spectroscopy published by Corbin & Boroson (1996) shows a flat optical spectrum and a red UV contin- (Chen et al 1989). Corbbet et al (1998) note that the Hα profile is extremely broad and has two prominent peaks displaced by 4970 ± 150 and 7200 ± 300 km s −1 to the blue and red, respectively, of the narrow component of Hα.…”

Section: Notes On Individual Objectsmentioning

confidence: 99%

A 0.8–2.4μm spectral atlas of active galactic nuclei

Riffel

Rodríguez-Ardila²,

Pastoriza

2006

A&A

197

286

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Aims. We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN) of all degrees of activity in the wavelength interval of 0.8-2.4 µm, including the fluxes of the observed emission lines. We analyze the spectroscopic properties of the continuum and emission line spectra of the sources. Methods. In order to exclude aperture and seeing effects we used near-infrared spectroscopy in the short cross-dispersed mode (SXD, 0.8-2.4 µm), taking the JHK-bands spectra simultaneously.Results. We present the most extensive NIR spectral atlas of AGN to date. This atlas offers a suitable database for studying the continuum and line emission properties of these objects in a region full of interesting features. The shape of the continuum of QSOs and Sy 1's are similar, being essentially flat in the H and K bands, while a strong variation is found in the J band. In Seyfert 2 galaxies, the continuum in the Fλ × λ space smoothly decreases in flux from 1.2 µm redwards in almost all sources. In J, it smoothly rises bluewards in some sources, while in others a small decrease in flux is observed. The spectra are dominated by strong emission

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“…This makes measurement of the flux and width of Mg ii difficult. Following several other authors (e.g., Corbin & Boroson 1996;Dietrich et al 2002), we developed an Fe ii template from the medium-resolution HST spectrum from I Zw 1 following the procedure used by Vestergaard & Wilkes (2001). We adjusted the amplitude of the Fe ii template so that it fitted the Fe ii feature in the spectra.…”

Section: Mg II Regg Ionmentioning

confidence: 99%

Hubble Space TelescopeSTIS Ultraviolet Spectral Evidence of Outflow in Extreme Narrow‐Line Seyfert 1 Galaxies. I. Data and Analysis

Leighly

Moore

2004

ApJ

145

175

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We present Hubble Space Telescope (HST ) Space Telescope Imaging Spectrograph observations of two extreme narrow-line Seyfert 1 galaxies ( NLS1's), IRAS 13224À3809 and 1H 0707À495. The spectra are characterized by very blue continua; broad, strongly blueshifted high-ionization lines (including C iv and N v); and narrow, symmetric intermediate-(including C iii], Si iii], and Al iii) and low-ionization (e.g., Mg ii) lines centered at the rest wavelength. The emission-line profiles suggest that the high-ionization lines are produced in a wind and that the intermediate-and low-ionization lines are produced in low-velocity gas associated with the accretion disk or base of the wind. In this paper, we present the analysis of the spectra from these two objects; in a companion paper, we present photoionization analysis and a toy dynamical model for the wind. The highly asymmetric profile of C iv suggests that it is dominated by emission from the wind, so we develop a template for the wind from the C iv line. We model the bright emission lines in the spectra using a combination of this template and a narrow symmetric line centered at the rest wavelength. We also analyzed a comparison sample of Hubble Space Telescope spectra from 14 additional NLS1's and constructed a correlation matrix of emission-line and continuum properties. A number of strong correlations were observed, including several involving the asymmetry of the C iv line.

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Combined Ultraviolet and Optical Spectra of 48 Low-Redshift QSOs and the Relation of the Continuum and Emission-Line Properties

Cited by 115 publications

References 0 publications

Lyα emission-line reconstruction for high-zQSOs

Lyα emission-line reconstruction for high-zQSOs

A 0.8–2.4μm spectral atlas of active galactic nuclei

Hubble Space TelescopeSTIS Ultraviolet Spectral Evidence of Outflow in Extreme Narrow‐Line Seyfert 1 Galaxies. I. Data and Analysis

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