J/ApJ/633/638 Variable quasar sample from SDSS (Wilhite+, 2005)
Spectral variability of quasars in the Sloan Digital Sky Survey.
I. Wavelength dependence.
Wilhite B.C., Vanden Berk D.E., Kron R.G., Schneider D.P., Pereyra N.,
Brunner R.J., Richards G.T., Brinkmann J.V.
<Astrophys. J., 633, 638-648 (2005)>
=2005ApJ...633..638W 2005ApJ...633..638W
ADC_Keywords: Active gal. nuclei ; QSOs ; Photometry, SDSS ; Redshifts
Keywords: galaxies: active - quasars: general - techniques: spectroscopic
Abstract:
SDSS repeat spectroscopic observations have resulted in multiepoch
spectroscopy for 2500 quasars observed more than 50 days apart. From
this sample, calibrating against stars observed simultaneously, we
identify 315 quasars that have varied significantly between
observations (with respect to assumed nonvariable stars observed
concurrently). These variable quasars range in redshift from 0.5 to
4.72. This is the first large quasar sample studied spectroscopically
for variability and represents a potentially useful sample for future
high-redshift reverberation mapping studies. This also marks the first
time the precise wavelength dependence of quasar variability has been
determined, allowing both the continuum and emission-line variability
to be studied.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 62 315 Variable quasar sample
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See also:
VII/270 : SDSS quasar catalog: tenth data release (Paris+, 2014)
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
II/259 : The SDSS Photometric Catalog, Release 3 (Abazajian+ 2005)
J/ApJ/728/26 : QSO selection based on phot. variability (Macleod+, 2011)
J/A+A/525/A37 : Variability of QSOs in SDSS Stripe 82 (Meusinger+, 2011)
J/AJ/142/78 : New 2.2<z<3 quasars from SDSS and UKIDSS (Wu+, 2011)
J/ApJ/641/78 : CIV variability in 105 SDSS quasars (Wilhite+, 2006)
J/AJ/126/2579 : SDSS QSO catalog. II. First data release (Schneider+, 2003)
J/AJ/123/567 : SDSS quasar catalog. I. Early Data Release (Schneider+, 2002)
J/AJ/121/2308 : Sloan Digital Sky Survey quasar photometry (Richards+, 2001)
J/AJ/121/1872 : FIRST radio-selected QSOs (Helfand+, 2001)
J/A+A/321/123 : Optical variability of QSOs (Cristiani+ 1997)
J/MNRAS/268/305 : Variability of optically selected quasars (Hook+ 1994)
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSSJ SDSS name (HHMMSS.ss+DDMMSS.s) (1)
20- 24 I5 d MJD(H) Modified Julian Date of High-S/N data
26- 30 I5 d MJD(L) Modified Julian Date of Low-S/N data
32- 35 F4.2 --- z [0.5/4.8] Redshift (2)
37- 41 F5.1 d DelT [17.5/270.4] Rest-frame time lag Δτ
43- 46 F4.1 mag rmag [16.8/21.6] Apparent SDSS r band magnitude (2)
48- 52 F5.1 mag rMAG Absolute SDSS r band magnitude (2)
54- 57 F4.1 --- S/N(H) [1.7/54] SDSS r band High-S/N ratio
59- 62 F4.1 --- S/N(L) [0.7/42] SDSS r band Low-S/N ratio
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Note (1): Which includes right ascension and declination.
Note (2): From High-S/N data; magnitudes are given on the AB system.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 23-May-2006