Emission-line properties of optically and radio-selected complete quasar samples

Baldwin, J. A.; Wampler, E. J.; Gaskell, C. M.

doi:10.1086/167224

Cited by 88 publications

(80 citation statements)

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“…As new data became available similar correlations have been found for other emission lines (e.g. Baldwin et al 1989;Kinney et al 1990;Pogge & Peterson 1992;Green et al 2001). In Fig.…”

Section: Empirical Relationssupporting

confidence: 78%

QSFit: automatic analysis of optical AGN spectra

Calderone

Nicastro

Ghisellini

et al. 2017

Monthly Notices of the Royal Astronomical Society

105

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We present QSFit, a new software package to automatically perform the analysis of Active Galactic Nuclei (AGN) optical spectra. The software provides luminosity estimates for the AGN continuum, the Balmer continuum, both optical and UV iron blended complex, host galaxy and emission lines, as well as width, velocity offset and equivalent width of 20 emission lines.Improving on a number of previous studies on AGN spectral analysis, QSFit fits all the components simultaneously, using an AGN continuum model which extends over the entire available spectrum, and is thus a probe of the actual AGN continuum whose estimates are scarcely influenced by localized features (e.g. emission lines) in the spectrum.We used QSFit to analyze 71,251 optical spectra of Type 1 AGN at z < 2 (obtained by the Sloan Digital Sky Survey, SDSS) and to produce a publicly available catalog of AGN spectral properties. Such catalog allowed us (for the first time) to estimate the AGN continuum slope and the Balmer continuum luminosity on a very large sample, and to show that there is no evident correlation between these quantities the redshift.All data in the catalog, the plots with best fitting model and residuals, and the IDL code we used to perform the analysis, are available on a dedicated website. The whole fitting process is customizable for specific needs, and can be extended to analyze spectra from other data sources. The ultimate purpose of QSFit is to allow astronomers to run standardized recipes to analyze the AGN data, in a simple, replicable and shareable way.

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“…As new data became available similar correlations have been found for other emission lines (e.g. Baldwin et al 1989;Kinney et al 1990;Pogge & Peterson 1992;Green et al 2001). In Fig.…”

Section: Empirical Relationssupporting

confidence: 78%

QSFit: automatic analysis of optical AGN spectra

Calderone

Nicastro

Ghisellini

et al. 2017

Monthly Notices of the Royal Astronomical Society

105

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“…The comparison with reference samples of radio-quiet QSOs (e.g., Cristiani & Vio 1990;Francis et al 1991;Green 1996;Zheng et al 1997;Puchnarewicz et al 1997) yields a good agreement. On the other hand, our EW values are lower than those measured for pure samples of Seyfert 1 galaxies (Véron-Cetty et al 1983), reflecting the known luminosity dependence (Baldwin-effect;Baldwin 1977;Baldwin et al 1989). For the AGNs from the present sample, a significant anti-correlation between luminosity and EW is found only for C iii].…”

Section: Emission Linescontrasting

confidence: 67%

A QSO survey via optical variability and zero proper motion in the M 92 field

Meusinger¹,

Brunzendorf²

2001

A&A

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Abstract. The combination of variability and proper motion constraints (VPM search) is believed to provide an efficient yet unconventional search strategy for QSOs with selection effects quite different from conventional optical QSO surveys. We performed a VPM QSO search in a 10 square degrees field around M 92 on 162 selected digitised Schmidt plates in the Johnson B band with a time-baseline of more than three decades. In Paper I, we constructed a sample of VPM QSO candidates with B ≤ 19.7. The spectroscopic follow-up observations revealed 58 QSOs and 7 Seyfert 1 galaxies as well as 27 narrow-emission line galaxies. We present the lowresolution spectra and the data for the QSOs and Seyfert galaxies: AGN types, accurate positions, redshifts, mean B magnitudes, and colour indices, along with the selection parameters of the VPM search, i.e., indices for variability, proper motion, and image structure. The redshifts cover the interval 0 < ∼ z < ∼ 3; absolute magnitudes are in the range −21 < ∼ MB < ∼ −29. The statistical properties of the resulting QSO sample are studied in detail. No significant differences were found between our VPM QSO sample and published QSO samples from multicolour or spectroscopic surveys. The fraction of QSOs with unusual colours is estimated to be less than 5 per cent within the magnitude range B ≤ 19.7.

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“…Three AGN samples have been used in this work: (1) the Large Bright Quasar Survey (LBQS) sample and references therein), (2) a sample of 104 high-redshift, highluminosity quasars with ground-based spectrophotometry Baldwin, Wampler, &Gaskell (1987), andBaldwin (1977). Forster et al (2001) supplied monochromatic luminosities and FWHMs for many emission lines in about 1000 LBQS quasars.…”

Section: The Samplementioning

confidence: 99%

The Largest Black Holes and the Most Luminous Galaxies

Netzer

2003

The Astrophysical Journal

125

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The empirical relationship between the broad-line region size and the source luminosity in active galactic nuclei (AGNs) is used to obtain black hole (BH) masses for a large number of quasars in three samples. The largest black hole masses exceed and are found to occur in the objects with the highest luminosities. 1010 M , Such BH masses, when converted to galaxy bulge mass and luminosity, indicate masses in excess of 13 10 M , and in excess of 700 km s Ϫ1 . Such massive galaxies have never been observed. The largest BHs reside, almost j * exclusively, in high-redshift quasars. All this is inconsistent with several suggested scenarios of BH and galaxy formation. Possible ways out are that either the observed size-luminosity relationship in low-luminosity AGNs does not extend to very high luminosity or else the correlations observed in the local universe do M -M -j BH bulge * not reflect the relation between those quantities at the epoch of galaxy formation.

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Emission-line properties of optically and radio-selected complete quasar samples

Cited by 88 publications

References 0 publications

QSFit: automatic analysis of optical AGN spectra

QSFit: automatic analysis of optical AGN spectra

A QSO survey via optical variability and zero proper motion in the M 92 field

The Largest Black Holes and the Most Luminous Galaxies

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