J/MNRAS/430/3445 Covering factor of warm dust in quasars (Ma+, 2013)
The covering factor of warm dust in quasars:
a view from the Wide-field Infrared Survey Explorer All-Sky Data Release.
Ma X.-C., Wang T.-G.
<Mon. Not. R. Astron. Soc., 430, 3445-3452 (2013)>
=2013MNRAS.430.3445M 2013MNRAS.430.3445M
ADC_Keywords: QSOs ; Ultraviolet ; Galaxies, IR
Keywords: catalogues - galaxies: active - quasars: general - infrared: galaxies
Abstract:
By combining newly obtained infrared photometric data from the All-Sky
Data Release of the Wide-field Infrared Survey Explorer with
spectroscopic data from the Seventh Data Release of the Sloan Digital
Sky Survey, we study the covering factor of warm dust (CFWD) for a
large quasar sample, as well as the relations between CFWD and other
physical parameters of quasars. We find a strong correlation between
the flux ratio in the mid-infrared to near-ultraviolet and the slope
of the near-ultraviolet spectra, which is interpreted as a dust
extinction effect. After correcting for dust extinction utilizing the
above correlation, we examine the relations between CFWD and active
galactic nucleus properties: bolometric luminosity (Lbol), black
hole mass (MBH) and Eddington ratio (L/LEdd). We confirm the
anticorrelation between CFWD and Lbol. Further, we find that CFWD is
anticorrelated with MBH but is independent of L/LEdd. Radio-loud
quasars are found to follow the same correlations as radio-quiet
quasars. Monte Carlo simulations show that the anisotropy of the
UV-optical continuum of the accretion disc can have a significant
effect, but is not likely to dominate the CFWD-Lbol correlation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 75 16275 Primary data for all 16275 sources in our sample
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See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
VIII/90 : The FIRST Survey Catalog, Version 12Feb16 (Becker+ 2012)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- SDSS SDSS name (HHMMSS.ss+DDMMSS.s, Eq. J2000)
20- 24 F5.3 --- z Redshift
26- 31 F6.3 --- alpha [-3.1/0] NUV spectral slope α:
Fλ∝λα
33- 41 E9.4 cW/m2/nm FNUV NUV flux (erg/cm2/s/Å)
43- 51 E9.4 cW/m2/nm FMIR MIR flux (erg/cm2/s/Å)
53- 57 F5.3 --- CFWD [0/2] Covering factor
59- 64 F6.3 [10-7W] logLbol [44.6/47.5] Bolometric luminosity (erg/s)
66- 70 F5.3 [Msun] logMbh ?=* Black hole mass mass
72 I1 --- FS [0/1] Flag for non-primary source (1)
74- 75 I2 --- F1 [-1/2] FIRST flag (2)
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Note (1): flag as follows:
0 = the 12,483 sources in our primary sample
1 = the remaining 3792 sources, which only have upper limits for W3 or W4
magnitudes
Note (2): FIRST (Cat. VIII/90) radio flag (as in catalogue of Shen et al.,
2011, Cat. J/ApJS/194/45) as follows:
-1 = not in FIRST print
0 = FIRST undetected
1 = core-dominant
2 = lobe-dominant
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Apr-2014