Access to Astronomical Catalogues

← Click to display the menu
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
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:
FileName Lrecl Records Explanations
ReadMe 80 . This file table5.dat 281 5546 Bayesian quasar candidates table6.dat 281 592 Wedge quasar candidates table7.dat 99 23 XMM-Newton objects in the XFLS area
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) : SDSS Home Page Byte-by-byte Description of file: table[56].dat
Bytes Format Units Label Explanations
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
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). Note (6): From Richards et al. (2009ApJS..180...67R).
Byte-by-byte Description of file: table7.dat
Bytes Format Units Label Explanations
1 A1 --- --- [X] 2- 19 A18 --- XName Name ( 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
Nomenclature Notes: In SIMBAD, sources are [RDL2009] NNNN (Tables 5-6) or [RDL2009] (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) 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) Fadda06 = Fadda et al. (2006AJ....131.2859F)
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
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service