J/ApJ/779/104 Luminous dust-poor SDSS QSOs at z<4.5 (Jun+, 2013)
Physical properties of luminous dust-poor quasars.
Jun H.D., Im M.
<Astrophys. J., 779, 104 (2013)>
=2013ApJ...779..104J 2013ApJ...779..104J
ADC_Keywords: QSOs ; Redshifts ; Surveys
Keywords: galaxies: active; galaxies: evolution; infrared: galaxies;
quasars: general
Abstract:
We identify and characterize a population of luminous, dust-poor
quasars at 0<z<5 that is photometrically similar to objects previously
found at z>6. This class of active galactic nuclei is known to show
little IR emission from dusty structure, but it is poorly understood
in terms of number evolution and dependence on physical quantities. To
better understand the properties of these quasars, we compile a
rest-frame UV to IR library of 41000 optically selected type 1 quasars
with Lbol>1045.7erg/s. After fitting the broadband spectral energy
distributions (SEDs) with accretion disk and dust components, we find
0.6% of our sample to be hot dust-poor, with rest-frame 2.3µm to
0.51µm flux density ratios of -0.5dex or less. The dust-poor SEDs
are blue in the UV-optical and weak in the mid-IR, such that their
accretion disks are less obscured and the hot dust emission traces
that of warm dust down to the dust-poor regime. At a given bolometric
luminosity, dust-poor quasars are lower in black hole mass and higher
in Eddington ratio than general luminous quasars, suggesting that they
are in a rapidly growing evolutionary state in which the dust-poor
phase appears as a short or rare phenomenon. The dust-poor fraction
increases with redshift, and possible implications for their evolution
are discussed.
Description:
In this paper, we aim to identify the lower redshift counterparts
of the high-redshift, hot dust-poor quasars of J10 (Jiang et al.
2010Natur.464..380J 2010Natur.464..380J). The search for hot dust-poor quasars is based on
the SDSS Quasar Catalog (DR9 edition; Schneider et al. 2010, VII/260;
superseded by Paris et al. 2012, VII/269).
In addition to the SDSS optical imaging and spectroscopic data, we
gathered UV through MIR imaging data from the Galaxy Evolution
Explorer (GALEX), the Two Micron All Sky Survey (2MASS), the UKIRT
Infrared Deep Sky Survey (UKIDSS), and WISE.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 91 233 Hot dust-poor quasar properties
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See also:
VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
VIII/90 : The FIRST Survey Catalog, Version 12Feb16 (Becker+ 2012)
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/MNRAS/434/3104 : QSOs SED shapes from optical to NIR (Hao+, 2013)
J/MNRAS/430/3445 : Covering factor of warm dust in quasars (Ma+, 2013)
J/ApJS/206/4 : SED & bolometric corrections for QSOs (Krawczyk+, 2013)
J/AJ/144/49 : Quasars from SDSS-DR7, WISE and UKIDSS surveys (Wu+, 2012)
J/ApJ/753/125 : NIR spectroscopy follow-up of 60 SDSS-DR7 QSOs (Shen+, 2012)
J/ApJS/194/45 : QSO properties from SDSS-DR7 (Shen+, 2011)
J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)
J/A+A/512/A34 : XMM-COSMOS Type 1 AGNs (Lusso+, 2010)
J/ApJS/180/67 : Photometric selection of QSOs from SDSS. II. (Richards+, 2009)
J/MNRAS/392/19 : The 2dF-SDSS QSO survey (Croom+, 2009)
J/ApJ/698/1095 : The FIRST-2MASS red QSO survey. II. (Urrutia+, 2009)
J/ApJ/692/758 : BAL QSOs in SDSS-DR5 (Gibson+, 2009)
J/ApJ/680/169 : SDSS DR5 virial black hole masses (Shen+, 2008)
J/ApJS/166/470 : SDSS-Spitzer type I QSOs IR photometry (Richards+, 2006)
J/ApJ/640/579 : Near-infrared spectra of 27 SDSS quasars (Glikman+, 2006)
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- 19 A19 --- Name Quasar name (JHHMMSS.ss+DDMMSS.s)
21- 25 F5.3 --- z [0.3/4.5] SDSS redshift
27 A1 --- l_f2.3 Limit flag on f2.3
28- 33 F6.2 [-] f2.3 [-0.9/-0.5] Log of 2.3µm to optical
flux ratio (1)
35- 38 F4.2 [-] e_f2.3 [0.01/0.4] Uncertainty in f2.3
40 A1 --- l_f10 Limit flag on f10
41- 46 F6.2 [-] f10 [-0.6/0.2]?=99 Log of 10µm to optical
flux ratio (1)
48- 52 F5.2 [-] e_f10 [0.02/0.3]?=99 Uncertainty in f10
54- 59 F6.3 [10-7W] logLbol [45.7/48.1] Log of Bolometric luminosity;
in erg/s units
61- 65 F5.3 [10-7W] e_logLbol [0.004/0.1] Uncertainty in logLbol
67- 71 F5.2 [Msun] logMBH [7.7/10.1]?=99 Log of black hole mass
73- 77 F5.2 [Msun] e_logMBH [0.01/1.1]?=99 Uncertainty in logMBH
79- 84 F6.3 --- fEdd [0.02/5]?=99 Eddington ratio fEdd
86- 91 F6.3 --- e_fEdd [0.004/3]?=99 Uncertainty in FEdd
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Note (1): Fluxes are relative to optical (0.51µm):
fλ = log(Lλ/L0.51) = log(λFλ/0.51F0.51)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 30-Apr-2015