J/MNRAS/375/989 Quasar variability (Wold+, 2007)
The dependence of quasar variability on black hole mass.
Wold M., Brotherton M.S., Shang Z.
<Mon. Not. R. Astron. Soc., 375, 989-999 (2007)>
=2007MNRAS.375..989W 2007MNRAS.375..989W
ADC_Keywords: QSOs ; Redshifts
Keywords: quasars: general
Abstract:
In order to investigate the dependence of quasar variability on
fundamental physical parameters like black hole mass, we have matched
quasars from the Quasar Equatorial Survey Team, Phase 1 (QUEST1)
variability survey with broad-lined objects from the Sloan Digital Sky
Survey. The matched sample contains 104 quasars, and the Sloan spectra
are used to estimate black hole masses and bolometric luminosities.
Variability amplitudes are measured from the QUEST1 light curves. We
find that black hole mass correlates with several measures of the
variability amplitude at the 99 per cent significance level or better.
The correlation does not appear to be caused by obvious selection
effects inherent to flux-limited quasar samples, host galaxy
contamination or other well-known correlations between quasar
variability and luminosity/redshift. We evaluate variability as a
function of rest-frame time lag using structure functions and find
further support for the variability-black hole mass correlation.
Description:
The sample was formed by matching objects categorized as having broad
emission lines at redshifts z<0.75 in the SDSS DR2 (Abazajian et al.,
2004AJ....128..502A 2004AJ....128..502A, http://www.sdss.org/dr2/ ) with sources in the
200k Light Curve Catalogue of the QUEST1 variability survey (Rengstorf
et al., 2004, Cat. II/266).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 110 104 The total sample of 104 quasars with variability
measurements and AGN parameters
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See also:
II/266 : QUEST1 200k light curve catalog (Rengstorf+, 2004)
http://www.sdss.org : SDSS Home Page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSS SDSS ID number
20- 24 F5.3 --- z Redshift
26- 30 F5.2 mag rmag Apparent Sloan r magnitude
32- 37 F6.2 mag iMAG Absolute magnitude in Sloan i filter
39- 43 F5.3 mag e_ Weighted standard deviation of the distribution
of variability amplitudes in the R filter
45- 49 F5.3 mag Mean standard deviation of the distribution
of variability amplitudes in the R filter
51- 55 F5.3 mag Med(DR) Median standard deviation of the distribution
of variability amplitudes in the R filter
57- 61 F5.3 mag Max(DR) Maximum standard deviation of the distribution
of variability amplitudes in the R filter
63- 67 F5.3 mag e_ Weighted standard deviation of the distribution
of variability amplitudes in the V filter
69- 73 F5.3 mag Mean standard deviation of the distribution
of variability amplitudes in the V filter
75- 79 F5.3 mag Med(DV) Median standard deviation of the distribution
of variability amplitudes in the V filter
81- 85 F5.3 mag Max(DV) Maximum standard deviation of the distribution
of variability amplitudes in the V filter
87- 91 F5.3 [solMass] logMBH log of black hole mass
93- 97 F5.2 [10-7W] logLbol log of bolometric luminosity
99-103 F5.2 [---] logER log of Eddington ratio defined as Lbol/LEdd
105-110 F6.2 % GCL Global confidence level of variability as
defined by Rengstorf et al. (2004,
Cat. II/266)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Sep-2007