J/AJ/137/3884 Quasar candidates selected from the SDSS (Richards+, 2009)
Eight-dimensional mid-infrared/optical Bayesian quasar selection.
Richards G.T., Deo R.P., Lacy M., Myers A.D., Nichol R.C., Zakamska N.L.,
Brunner R.J., Brandt W.N., Gray A.G., Parejko J.K., Ptak A.,
Schneider D.P., Storrie-Lombardi L.J., Szalay A.S.
<Astron. J., 137, 3884-3899 (2009)>
=2009AJ....137.3884R 2009AJ....137.3884R
ADC_Keywords: Galaxies, IR ; QSOs ; Surveys
Keywords: catalogs - infrared: galaxies - methods: statistical -
quasars: general
Abstract:
We explore the multidimensional, multiwavelength selection of quasars
from mid-infrared (MIR) plus optical data, specifically from
Spitzer-Infrared Array Camera (IRAC) and the Sloan Digital Sky Survey
(SDSS). Traditionally, quasar selection relies on cuts in
two-dimensional color space despite the fact that most modern surveys
(optical and IR) are done in more than three bandpasses. In this
paper, we apply modern statistical techniques to combined Spitzer MIR
and SDSS optical data, allowing up to eight-dimensional (8-D) color
selection of quasars. Using a Bayesian selection method, we catalog
5546 quasar candidates to an 8.0µm depth of 56µJy over an area
of ∼24°2. Roughly 70% of these candidates are not identified by
applying the same Bayesian algorithm to 4-color SDSS optical data
alone. The 8-D optical+MIR selection on this data set recovers 97.7%
of known type 1 quasars in this area and greatly improves the
effectiveness of identifying 3.5<z<5 quasars which are challenging to
identify (without considerable contamination) using MIR data alone.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 281 5546 Bayesian quasar candidates
table6.dat 280 592 Wedge quasar candidates
table7.dat 99 23 XMM-Newton objects in the XFLS area
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
II/282 : SDSS Photometric Catalog, Release 6 (Adelman-McCarthy+, 2007)
VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)
VII/252 : SDSS-DR5 quasar catalog (Schneider+, 2007)
http://www.sdss.org : SDSS Home Page
Byte-by-byte Description of file: table[56].dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/6138] Unique catalog number,
<[RDL2009] NNNN> in Simbad
6- 15 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
17- 25 F9.6 deg DEdeg Declination in decimal degrees (J2000)
27- 44 A18 --- SDSS SDSS Name (JHHMMSS.SS+DDMMSS.S)
46- 63 A18 --- ID SDSS Object ID
65- 70 F6.3 mag umag SDSS u band PSF asinh magnitude (1)
72- 77 F6.3 mag gmag SDSS g band PSF asinh magnitude (1)
79- 84 F6.3 mag rmag SDSS r band PSF asinh magnitude (1)
86- 91 F6.3 mag imag SDSS i band PSF asinh magnitude (1)
93- 98 F6.3 mag zmag SDSS z band PSF asinh magnitude (1)
100-107 F8.3 uJy F3.6 Spitzer/IRAC 3.6 micron band flux density
109-116 F8.3 uJy F4.5 Spitzer/IRAC 4.5 micron band flux density
118-125 F8.3 uJy F5.8 Spitzer/IRAC 5.8 micron band flux density
127-134 F8.3 uJy F8.0 Spitzer/IRAC 8.0 micron band flux density
136-141 F6.3 mag e_umag Error in umag
143-148 F6.3 mag e_gmag Error in gmag
150-154 F5.3 mag e_rmag Error in rmag
156-160 F5.3 mag e_imag Error in imag
162-166 F5.3 mag e_zmag Error in zmag
168-174 F7.3 uJy e_F3.6 Error in F3.6
176-182 F7.3 uJy e_F4.5 Error in F4.5
184-190 F7.3 uJy e_F5.8 Error in F5.8
192-198 F7.3 uJy e_F8.0 Error in F8.0
200-204 F5.3 mag Au The u band Galactic extinction (2)
206 I1 --- cl [3/6] SDSS Morphology (6=point, 3=extended)
208 I1 --- wL [0/1] Lacy wedge region flag (1=in, 0=out)
210 I1 --- wS [0/1] Stern wedge region flag (1=in, 0=out)
212 I1 --- wSm [0/1] Modified Stern wedge flag (1=in, 0=out)
214 I1 --- cl8 [0/1] 8-D Bayesian classification (1=in, 0=out)
216 I1 --- cl6 [0/1] 6-D Bayesian classification (1=in, 0=out)
218-221 F4.2 --- zph8 8-D photometric redshift (5)
223-226 F4.2 --- e_zph8 Lower limit on zph8
228-231 F4.2 --- E_zph8 Upper limit on zph8
233-237 F5.3 --- zpr8 8-D photometric redshift range probability
239-242 F4.2 --- zph6 6-D photometric redshift (5)
244-247 F4.2 --- e_zph6 Lower limit on zph6
249-252 F4.2 --- E_zph6 Upper limit on zph6
254-258 F5.3 --- zpr6 6-D photometric redshift range probability
260 I1 --- O [0/1] Optical selection flag (6)
262-271 A10 --- P-ID Previous catalog identification with
morphological type (G1)
273-281 F9.6 --- P-z Previous catalog object redshift
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Note (1): Corrected for Galactic extinction.
Note (2): Where Au/Ag/Ar/Ai/Az = 5.155/3.793/2.751/2.086/1.479 * E(B-V).
Note (5): See Weinstein et al. (2004ApJS..155..243W 2004ApJS..155..243W).
Note (6): From Richards et al. (2009ApJS..180...67R 2009ApJS..180...67R).
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1 A1 --- --- [X]
2- 19 A18 --- XName Name (XHHMMSS.ss+DDMMSS.s)
21- 30 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
32- 40 F9.6 deg DEdeg Declination in decimal degrees (J2000)
42- 45 F4.1 ks Exp XMM-Newton exposure time
47- 57 E11.4 mW/m2 Ftot ? Total flux
59- 63 F5.1 ct Scts ? Soft-band counts (background corrected)
65- 68 F4.1 ct Hcts ? Hard-band counts (background corrected)
70- 74 F5.2 --- HR ? Hardness ratio
76- 79 F4.2 --- e_HR ? Error in HR
81- 84 I4 --- Seq ? Quasar catalog number
86- 92 A7 --- P-ID Previous catalog identification with
morphological type (G1)
95- 99 F5.3 --- P-z ? Previous catalog object redshift
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Nomenclature Notes:
In SIMBAD, sources are [RDL2009] NNNN (Tables 5-6) or
[RDL2009] XHHMMSS.ss+DDMMSS.s (Table 7).
Global Notes:
Note (G1): Previous catalog classification from sources:
2QZ = 2dF QSO Redshift Survey (2004, Cat. VII/241)
2SLAQ = SDSS-2dF LRG and QSO Survey (2SLAQ) Early Data Release quasar catalog
(Croom et al., 2009MNRAS.392...19C 2009MNRAS.392...19C)
DR5QSO = DR5 quasar catalog (Schneider et al., 2007, Cat. VII/252)
DR6 = SDSS-DR6 spectroscopic database (Adelman-McCarthy et al. Cat. II/282)
T07 = Trump et al. (2007, Cat. J/ApJS/172/383)
P06 = Papovitch et al. (2006, Cat. J/AJ/132/231)
U = Unknown
Lacy05 = Lacy et al. (2005ApJS..161...41L 2005ApJS..161...41L)
Fadda06 = Fadda et al. (2006AJ....131.2859F 2006AJ....131.2859F)
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History:
From electronic version of the journal
29-Sep-2011 : In table 7 (col. P-ID), P96QSO is a misprint for P06QSO.
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 23-Sep-2011