J/A+A/568/A114 SDSS quasars with weak emission lines (Meusinger+, 2014)
A large sample of Kohonen-selected SDSS quasars with weak emission lines:
selection effects and statistical properties.
Meusinger H., Balafkan N.
<Astron. Astrophys. 568, A114 (2014)>
=2014A&A...568A.114M 2014A&A...568A.114M
ADC_Keywords: Active gal. nuclei ; QSOs
Keywords: quasars: general - quasars: emission lines
Abstract:
A tiny fraction of the quasar population shows remarkably weak
emission lines. Several hypotheses have been developed, but the weak
line quasar (WLQ) phenomenon still remains puzzling. The aim of this
study was to create a sizeable sample of WLQs and WLQ-like objects and
to evaluate various properties of this sample.
We performed a search for WLQs in the spectroscopic data from the
Sloan Digital Sky Survey Data Release 7 based on Kohonen
self-organising maps for nearly 105 quasar spectra. The final sample
consists of 365 quasars in the redshift range z=0.6-4.2
(z{bar}=1.50±0.45) and includes in particular a subsample of 46 WLQs
with equivalent widths WMgII<11Å and WCIV<4.8Å We compared
the luminosities, black hole masses, Eddington ratios, accretion
rates, variability, spectral slopes, and radio properties of the WLQs
with those of control samples of ordinary quasars. Particular
attention was paid to selection effects.
Description:
We present a catalogue of 365 quasars with weak emission lines from
the Sloan Digital Ska Survey Data Release 7. The selection procedure
is based on a combination of the power of self-organizing maps
produced by neural networks and the visual inspection of a large
number of spectra. The catalogue includes luminosities, virial black
hole masses, Edington ratios, accretion rates, SDSS and WISE
magnitudes, radio properties and variability estimators.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
wlq.dat 235 365 SDSS quasars with weak emission lines
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See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
VIII/90 : The FIRST Survey Catalog, Version 12Feb16 (Becker+ 2012)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/A+A/525/A37 : QSOs variability indexes in SDSS Stripe 82 (Meusinger+, 2011)
J/A+A/560/A104 : UV variability of quasars (Meusinger+, 2013)
Byte-by-byte Description of file: wlq.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSS SDSS designation (HHMMSS.ss+DDMMSS.s)
20- 24 F5.3 --- z Spectroscopic redshift (1)
26- 36 E11.6 0.1nm EWMgII ?=-9.99 Equivalent width of MgII (1)
38- 48 E11.6 0.1nm EWCIV ?=-9.99 Equivalent width of CIV (1)
50- 56 F7.4 [10-7W] logL3000 ?=-9.99 log luminosity at 300nm (3000Å) (1)
58- 64 F7.4 [10-7W] logLbol log Bolometric luminosity (1)
66- 70 F5.2 --- alpha [-2.8/0.2]?=-9.99 Spectral index (2)
72- 78 F7.4 [Msun] logMbh log black hole mass (1)
80- 86 F7.4 --- logEdd log Eddington ratio (1)
88- 96 F9.4 [Msun/yr] logAcc ?=-9.99 log accretion rate (2)
98-103 F6.3 mag umag ?=-9.99 SDSS u band PSF magnitude (1)
105-110 F6.3 mag gmag ?=-9.99 SDSS g band PSF magnitude (1)
112-117 F6.3 mag rmag ?=-9.99 SDSS r band PSF magnitude (1)
119-124 F6.3 mag imag ?=-9.99 SDSS i band PSF magnitude (1)
126-131 F6.3 mag zmag ?=-9.99 SDSS z band PSF magnitude (1)
133-138 F6.3 mag W1mag ?=-9.99 WISE W1 band magnitude (3)
140-145 F6.3 mag W2mag ?=-9.99 WISE W2 band magnitude (3)
147-152 F6.3 mag W3mag ?=-9.99 WISE W3 band magnitude (3)
154-159 F6.3 mag W4mag ?=-9.99 WISE W4 band magnitude (3)
161-162 I2 --- Rflag [-1/2] FIRST radio flag (1) (5)
164-170 F7.2 --- RL ?=-9.99 Radio loudness (R=F6cm/F2500Å) (1)
172-183 E12.6 [mag+2] logVu ?=-9.99 u band variability (4)
185-196 E12.6 [mag+2] logVg ?=-9.99 g band variability (4)
198-209 E12.6 [mag+2] logVr ?=-9.99 r band variability (4)
211-222 E12.6 [mag+2] logVi ?=-9.99 i band variability (4)
224-235 E12.6 [mag+2] logVz ?=-9.99 z band variability (4)
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Note (1): from Shen et al. 2011ApJS..194...45S 2011ApJS..194...45S, Cat. J/ApJS/194/45.
Note (2): from Meusinger & Weiss 2013A&A...560A.104M 2013A&A...560A.104M, Cat. J/A+A/560/A104.
[α=dlog(Fλ)/dlog(λ)]
Note (3): from WISE All-Sky Source Catalog (Wright et al. 2010AJ....140.1868W 2010AJ....140.1868W),
See Cat. II/311 and II/328.
Note (4): from Meusinger et al. 2011A&A...525A..37M 2011A&A...525A..37M, Cat. J/A+A/525/A37.
(variance of the magnitude differences)
Note (5): FIRST (Cat. VIII/90) radio flag as follows:
-1 = not in FIRST footprint
0 = FIRST undetected
1 = core-dominant
2 = lobe-dominant (radio morphology classification following Jiang et al.,
2007ApJ...656..680J 2007ApJ...656..680J)
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Acknowledgements:
Helmut Meusinger, meus(at)tls-tautenburg.de
(End) Helmut Meusinger [TLS, Germany], Patricia Vannier [CDS] 30-Jun-2014