J/ApJS/219/39 QSOs selection from SDSS and WISE (Richards+, 2015)
Bayesian high-redshift quasar classification from optical and mid-IR photometry.
Richards G.T., Myers A.D., Peters C.M., Krawczyk C.M., Chase G., Ross N.P.,
Fan X., Jiang L., Lacy M., McGreer I.D., Trump J.R., Riegel R.N.
<Astrophys. J. Suppl. Ser., 219, 39 (2015)>
=2015ApJS..219...39R 2015ApJS..219...39R (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Photometry, SDSS ; Photometry, infrared ; Redshifts
Keywords: catalogs; infrared: galaxies; methods: statistical; quasars: general
Abstract:
We identify 885503 type 1 quasar candidates to i≲22 using the
combination of optical and mid-IR photometry. Optical photometry is
taken from the Sloan Digital Sky Survey-III: Baryon Oscillation
Spectroscopic Survey (SDSS-III/BOSS), while mid-IR photometry comes
from a combination of data from the Wide-field Infrared Survey
Explorer (WISE) "AllWISE" data release and several large-area Spitzer
Space Telescope fields. Selection is based on a Bayesian kernel
density algorithm with a training sample of 157701 spectroscopically
confirmed type 1 quasars with both optical and mid-IR data. Of the
quasar candidates, 733713 lack spectroscopic confirmation (and 305623
are objects that we have not previously classified as photometric
quasar candidates). These candidates include 7874 objects targeted as
high-probability potential quasars with 3.5<z<5 (of which 6779 are new
photometric candidates). Our algorithm is more complete to z>3.5 than
the traditional mid-IR selection "wedges" and to 2.2<z<3.5 quasars
than the SDSS-III/BOSS project. Number counts and luminosity function
analysis suggest that the resulting catalog is relatively complete to
known quasars and is identifying new high-z quasars at z>3. This
catalog paves the way for luminosity-dependent clustering
investigations of large numbers of faint, high-redshift quasars and
for further machine-learning quasar selection using Spitzer and WISE
data combined with other large-area optical imaging surveys.
Description:
We construct the master quasar catalog by gathering samples of
spectroscopically confirmed quasars within the SDSS-I/II/III (York et
al. 2000AJ....120.1579Y 2000AJ....120.1579Y; Eisenstein et al. 2011AJ....142...72E 2011AJ....142...72E)
footprint.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
master.dat 383 1604577 *Master quasar catalog (table 1)
cand.dat 410 885503 *Optical+MIR photometric quasar candidates
catalog (table 2)
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Note on master.dat: original FITS file available in the FTP
(file name=masterquasarcatalogs.011414.fits).
Note on cand.dat: original FITS file available in the FTP
(file name=opticalirquasar_candidates.052015.fits).
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See also:
II/328 : AllWISE Data Release (Cutri+ 2013)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
IX/45 : The Chandra Source Catalog, Release 1.1 (Evans+ 2012)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)
J/ApJS/213/12 : SDSS Stripe 82 co-added runs (Jiang+, 2014)
J/ApJ/773/14 : BOSS: quasar luminosity function (Ross+, 2013)
J/ApJ/772/26 : AGN with WISE. II. The NDWFS Bootes field (Assef+, 2013)
J/ApJS/206/4 : SED for luminous QSOs (Krawczyk+, 2013)
J/ApJ/768/105 : z∼5 QSO luminosity function from SDSS (McGreer+, 2013)
J/MNRAS/424/2876 : Large area KX quasar catalogue (Maddox+, 2012)
J/AJ/144/49 : Quasars from SDSS-DR7, WISE and UKIDSS surveys (Wu+, 2012)
J/ApJS/200/8 : AGES: the AGN and Galaxy Evolution Survey (Kochanek+, 2012)
J/ApJS/199/3 : The quasars MMT-BOSS pilot survey (Ross+, 2012)
J/ApJ/742/61 : Phot. redshift of AGNs from XMM- and C-COSMOS (Salvato+ 2011)
J/ApJS/195/10 : The CDF-S survey: 4Ms source catalogs (Xue+, 2011)
J/ApJ/728/23 : GALEX UV-bright high-redshift quasars (Worseck+, 2011)
J/ApJ/719/1672 : SDSS binary quasars at high redshift. I. (Hennawi+, 2010)
J/MNRAS/405/2302 : Improved redshifts for SDSS quasar spectra (Hewett+, 2010)
J/ApJ/716/348 : The XMM-Newton survey of the COSMOS field (Brusa+, 2010)
J/ApJ/713/970 : Low-resolution SED templates for AGNs & gal. (Assef+, 2010)
J/ApJ/710/1498 : QSO luminosity function at z∼4 (Glikman+, 2010)
J/ApJ/701/428 : The Spitzer Deep, Wide-Field Survey (SDWFS) (Ashby+, 2009)
J/ApJ/696/1195 : COSMOS AGN spectroscopic survey. I. (Trump+, 2009)
J/AJ/137/3884 : Quasar candidates selected from the SDSS (Richards+, 2009)
J/ApJ/693/8 : High-redshift QSOs in the COSMOS survey (Brusa+, 2009)
J/MNRAS/392/19 : The 2dF-SDSS QSO survey (Croom+, 2009)
J/ApJS/180/67 : Phot. selection of quasars from SDSS. II. (Richards+, 2009)
J/ApJS/172/70 : zCOSMOS-bright catalog (Lilly+, 2007)
J/AJ/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)
J/AJ/132/999 : SDSS quasar lens search (Oguri+, 2006)
J/AJ/132/231 : MMT redshift survey of 24um sources (Papovich+, 2006)
J/ApJ/644/100 : SDSS quasars in the COSMOS field (Prescott+, 2006)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/ApJS/155/257 : NBC Quasar Candidate Catalog (Richards+, 2004)
http://www.sdss3.org/ : SDSS-III home page
Byte-by-byte Description of file: master.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.6 deg RAdeg Right ascension in decimal degrees (J2000)
12- 21 F10.6 deg DEdeg Declination in decimal degrees (J2000)
23- 26 I4 --- Run [94/8162] SDSS run number (1)
28- 30 I3 --- Rerun [301] SDSS rerun number
32 I1 --- Camcol [1/6] SDSS camera column
34- 36 I3 --- Field [11/999] SDSS field number
38- 41 I4 --- ID [1/8138] SDSS ID number within the field
43 I1 --- OT [3/6] SDSS object type (stellar=3, extended=6)
(OBJC_TYPE)
45- 55 I11 --- Flags SDSS object flags (OBJC_FLAGS) (2)
57- 65 I9 --- Flags2 SDSS object flags (OBJC_FLAGS2)
67- 71 F5.3 mag Au [0.01/6.2] Magnitudes of Galactic extinction
in u-band (EXTINCTION_U)
73- 77 F5.3 mag Ag [0.009/4.6] Magnitudes of Galactic extinction
in g-band (EXTINCTION_G)
79- 83 F5.3 mag Ar [0.006/3.3] Magnitudes of Galactic extinction
in r-band (EXTINCTION_R)
85- 89 F5.3 mag Ai [0.005/2.5] Magnitudes of Galactic extinction
in i-band (EXTINCTION_I)
91- 95 F5.3 mag Az [0.003/1.8] Magnitudes of Galactic extinction
in i-band (EXTINCTION_Z)
97-102 F6.1 --- Fupsf [-27.7/2882.1] PSF flux in u-band (PSFFLUX_U)
104-109 F6.1 --- Fgpsf [-10.9/8313] PSF flux in g-band (PSFFLUX_G)
111-117 F7.1 --- Frpsf [-0.6/11314.1] PSF flux in r-band (PSFFLUX_R)
119-125 F7.1 --- Fipsf [-31.1/12356.4] PSF flux in i-band (PSFFLUX_I)
127-133 F7.1 --- Fzpsf [-2.1/12640.6] PSF flux in z-band (PSFFLUX_Z)
135-139 F5.1 --- IVFu [0/232.2] Inverse variance of point-spread
function flux in u-band (PSFFLUXIVARU)
141-145 F5.1 --- IVFg [0/645.8] Inverse variance of point-spread
function flux in g-band (PSFFLUXIVARG)
147-151 F5.1 --- IVFr [0/307.8] Inverse variance of point-spread
function flux in r-band (PSFFLUXIVARR)
153-157 F5.1 --- IVFi [0/106.8] Inverse variance of point-spread
function flux in i-band (PSFFLUXIVARI)
159-161 F3.1 --- IVFz [0/8] Inverse variance of point-spread
function flux in z-band (PSFFLUXIVARZ)
163-169 F7.1 --- CoAFu [-6.5/2882.1]?=-9999 Co-added point-spread
function flux in u-band (PSFFLUXCLEANU)
171-177 F7.1 --- CoAFg [-11/8313]?=-9999 Co-added point-spread
function flux in g-band (PSFFLUXCLEANG)
179-185 F7.1 --- CoAFr [-3/11314.1]?=-9999 Co-added point-spread
function flux in r-band (PSFFLUXCLEANR)
187-193 F7.1 --- CoAFi [-4.4/12356.4]?=-9999 Co-added point-spread
function flux in i-band (PSFFLUXCLEANI)
195-201 F7.1 --- CoAFz [-19.8/12640.6]?=-9999 Co-added point-spread
function flux in z-band (PSFFLUXCLEANZ)
203-207 F5.1 --- IVCoAFu [0/722.2] Inverse variance of co-added
point-spread function flux in u-band
(PSFFLUXCLEANIVAR_U)
209-214 F6.1 --- IVCoAFg [0/2902] Inverse variance of co-added
point-spread function flux in g-band
(PSFFLUXCLEANIVAR_G)
216-221 F6.1 --- IVCoAFr [0/1215.2] Inverse variance of co-added
point-spread function flux in r-band
(PSFFLUXCLEANIVAR_R)
223-227 F5.1 --- IVCoAFi [0/579.1] Inverse variance of co-added
point-spread function flux in i-band
(PSFFLUXCLEANIVAR_I)
229-232 F4.1 --- IVCoAFz [0/36] Inverse variance of co-added
point-spread function flux in z-band
(PSFFLUXCLEANIVAR_Z)
234-235 I2 --- f_CoAFu [0/35] Flag indicating whether co-added
(CLEAN) flux should be used (PSFCLEANNUSE_U)
237-238 I2 --- f_CoAFg [0/35] Flag indicating whether co-added
(CLEAN) flux should be used (PSFCLEANNUSE_G)
240-241 I2 --- f_CoAFr [0/35] Flag indicating whether co-added
(CLEAN) flux should be used (PSFCLEANNUSE_R)
243-244 I2 --- f_CoAFi [0/35] Flag indicating whether co-added
(CLEAN) flux should be used (PSFCLEANNUSE_I)
246-247 I2 --- f_CoAFz [0/35] Flag indicating whether co-added
(CLEAN) flux should be used (PSFCLEANNUSE_Z)
249-253 F5.3 --- zBest1 [0.06/5.5]?=0 First zBest value (ZBEST1)
255-259 F5.3 --- zBest2 [0.1/3.6]?=0 Second zBest value (ZBEST2)
261-265 F5.3 --- zBest3 [0.06/4.9]?=0 Third zBest value (ZBEST3)
267-271 F5.3 --- zBest4 [0.1/5.2]?=0 Fourth zBest value (ZBEST4)
273-278 F6.3 --- zBest5 [-8/5]?=0 Fifth zBest value (ZBEST5)
280-284 F5.3 --- zBest6 [0.1/4.2]?=0 Sixth zBest value (ZBEST6)
286-290 F5.3 --- zBest7 [5.7/6.5]?=0 Seventh zBest value (ZBEST7)
292-296 F5.3 --- zBest8 [0.03/5.9]?=0 Eighth zBest value (ZBEST8)
298-302 F5.3 --- zBest9 [0.1/3.9]?=0 Ninth zBest value (ZBEST9)
304-309 F6.3 --- zBest10 [-1/6.3]?=0 Tenth zBest value (ZBEST10)
311-315 F5.3 --- zBest11 [0.3/5.5]?=0 Eleventh zBest value (ZBEST11)
317-321 F5.3 --- zBest12 [0.07/3.6]?=0 Twelfth zBest value (ZBEST12)
323-327 F5.3 --- zBest13 [3.8/5.1]?=0 Thirteenth zBest value (ZBEST13)
329-333 F5.3 --- zBest14 [0.1/4.2]?=0 Fourtheenth zBest value (ZBEST14)
335-339 I5 --- r_zBest [1/10113] Redshift source flag (SOURCEBIT) (3)
341 I1 --- Uni [0/1] Indicates whether the SDSS object
fell in the "uniform" selection area
(SDSS_UNIFORM) (4)
343 I1 --- QSO [0/1] AGES flag (AGES_QSO) (5)
345-351 I7 --- Code06 [-782208/786384] AGES flag (AGES_CODE06) (5)
353-357 F5.2 --- zphlo [-1/6] Minimum photometric redshift
(KDE_ZPHOTLO) (6)
359-363 F5.2 --- zphhi [-1/6.5] Maximum photometric redshift
(KDE_ZPHOTHI) (6)
365-369 F5.2 --- zphP [-1/1] Photometric redshift probability (6)
(KDE_ZPHOTPROB)
371 I1 --- UV? [0/1] Flag indicating a UV-excess or
low-redshift source (KDE_LOWZORUVX) (6)
373-376 F4.2 --- zpkP [0/1] Peak of the redshift probability
(XDQSOZ_PEAKPROB) (7)
378-381 F4.2 --- zpkFWHM [0/3.2] FWHM of the redshift peak (7)
(XDQSOZ_PEAKFWHM)
383 I1 --- Npk [0/8] Number of peaks in photo-z
distribution (XDQSOZ_NPEAKS) (7)
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Note (1): see http://classic.sdss.org/dr7/glossary/index.html
Note (2): see http://classic.sdss.org/dr7/products/catalogs/flags.html
Note (3): Bitwise flag from 20 to 213 indicating the redshift source as
coming from SDSS, 2QZ, AUS, AGES, COSMOS, FAN, BOSS, MMT, NBCKDE,
XDQSOZ, PAPOVICH, GLIKMAN, MADDOX, respectively.
Note (4): see Richards et al. (2002AJ....123.2945R 2002AJ....123.2945R)
Note (5): see Kochanek et al. (2012, J/ApJS/200/8)
Note (6): from Richards et al. (2009, J/ApJS/180/67)
Note (7): from Bovy et al. (2012ApJ...749...41B 2012ApJ...749...41B)
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Byte-by-byte Description of file: cand.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.6 deg RAdeg Right ascension (J2000)
12- 21 F10.6 deg DEdeg Declination (J2000)
23- 28 A6 --- Class Spectral classification (QSO, GALAXY, STAR,
CELG, ??, or U) (1)
30- 36 F7.5 --- zsp [0/6.7]? Spectroscopic redshift
38- 43 F6.3 mag umag [15/31.7] SDSS u-band AB magnitude,
corrected for Galactic extinction
45- 50 F6.3 mag gmag [15/27.4] SDSS g-band AB magnitude,
corrected for Galactic extinction
52- 57 F6.3 mag rmag [15/25.9] SDSS r-band AB magnitude,
corrected for Galactic extinction
59- 64 F6.3 mag imag [14.9/25] SDSS i-band AB magnitude,
corrected for Galactic extinction
66- 71 F6.3 mag zmag [15/24.5] SDSS z-band AB magnitude,
corrected for Galactic extinction
73- 78 F6.3 mag 3.6mag [12.8/23.8] 3.6um AB magnitude,
corrected for Galactic extinction
80- 85 F6.3 mag 4.5mag [12.5/24.2] 4.5um AB magnitude,
corrected for Galactic extinction
87- 92 F6.3 mag e_umag [0.003/99.99]?=99.99 Error on u-band magnitude
94- 99 F6.3 mag e_gmag [0.003/44] Error on g-band magnitude
101-106 F6.3 mag e_rmag [0.002/18] Error on r-band magnitude
108-113 F6.3 mag e_imag [0.002/21] Error on i-band magnitude
115-120 F6.3 mag e_zmag [0.003/16] Error on z-band magnitude
122-126 F5.3 mag e_3.6mag [0.02/0.7] Error on 3.6um magnitude
128-132 F5.3 mag e_4.5mag [0.01/0.7] Error on 4.5um magnitude
134-140 F7.2 3.63uJy Fu [-101/810] SDSS u-band flux density
in nanomaggies
142-147 F6.2 3.63uJy Fg [-1/759] SDSS g-band flux density
in nanomaggies
149-154 F6.2 3.63uJy Fr [-0.3/805] SDSS r-band flux density
in nanomaggies
156-161 F6.2 3.63uJy Fi [-0.3/979] SDSS i-band flux density
in nanomaggies
163-168 F6.2 3.63uJy Fz [-4/945] SDSS z-band flux density
in nanomaggies
170-177 F8.2 uJy F3.6 [1.1/25966] 3.6um flux density in microJy
179-186 F8.2 uJy F4.5 [0.8/35613] 4.5um flux density in microJy
188-192 F5.2 3.63uJy e_Fu [0.04/100] Error in u-band flux density
194-198 F5.2 3.63uJy e_Fg [0.02/54] Error in g-band flux density
200-204 F5.2 3.63uJy e_Fr [0.03/86] Error in r-band flux density
206-211 F6.2 3.63uJy e_Fi [0.04/163] Error in i-band flux density
213-218 F6.2 3.63uJy e_Fz [0.1/129] Error in z-band flux density
220-225 F6.2 uJy e_F3.6 [0.09/551] Error in 3.6um flux density
227-232 F6.2 uJy e_F4.5 [0.1/656] Error in 4.5um flux density
234-239 F6.3 mag Ymag [14.6/26]? Y-band Vega magnitude from UKIDSS
or VHS (2)
241-246 F6.3 mag Jmag [13.9/21]? J-band Vega magnitude from UKIDSS
or VHS (2)
248-253 F6.3 mag Hmag [13.2/20.3]? H-band Vega magnitude from UKIDSS
or VHS (2)
255-260 F6.3 mag Kmag [11.8/19.6]? K-band Vega magnitude from UKIDSS
or VHS (2)
262-267 F6.3 mag e_Ymag [0.003/46]? Error in Y-band magnitude
269-273 F5.3 mag e_Jmag [0.002/0.5]? Error in J-band magnitude
275-279 F5.3 mag e_Hmag [0.002/0.6]? Error in H-band magnitude
281-285 F5.3 mag e_Kmag [0.001/0.7]? Error in K-band magnitude
287-292 F6.3 mag FUV [13.7/24.8]? GALEX FUV magnitude (AB)
294-299 F6.3 mag NUV [13.8/24.8]? GALEX NUV magnitude (AB)
301-305 F5.3 mag e_FUV [0.008/0.6]? Error in FUV magnitude
307-311 F5.3 mag e_NUV [0.004/0.5]? Error in NUV magnitude
313-316 F4.1 --- gisig [-1/1]? Indicator of distance from mean g-i
color at ZHOTBEST (GI_SIGMA)
318-321 F4.2 mag Au [0.01/1] Extinction in SDSS u band
323-326 F4.2 --- den* [0/1.2] Star density from KDE algorithm
328-333 F6.2 --- denq [0/402] Quasar density from KDE algorithm
335-341 F7.3 --- b_zphO [0/100] Minimum photometric redshift [ugriz]
343-349 F7.3 --- zphO [0.005/100] Best photometric redshift [ugriz]
(ZPHOTBEST)
351-357 F7.3 --- B_zphO [0.01/100] Maximum photometric redshift [ugriz]
359-365 F7.3 --- zphOP [0.005/100] Probability of ZPHOTBEST being
between min and max (ZPHOTPROB)
367-370 F4.2 --- b_zphIR [0/6]? Minimum photometric redshift [ugrizJHK]
372-375 F4.2 --- zphIR [0.05/6.3]? Best photometric redshift
(ugrizJHK) (ZPHOTBESTJHK)
377-381 F5.3 --- B_zphIR [0.02/6.3]? Maximum photometric redshift
(ugrizJHK) (ZPHOTMAXJHK)
383-386 F4.2 --- zphIRP [0.2/1]? Probability of ZPHOTBESTJHK
being between min and max (ZPHOTPROBJHK)
388 I1 --- Leg [0/1] Indicates if object is in the
SDSS Legacy footprint
390 I1 --- Uni [0/1] Indicates if object was selected
according to Richards et al.
(2002AJ....123.2945R 2002AJ....123.2945R)
392-400 I9 --- Prim [0/673192456] SDSS primary target selection
flag; see Richards et al. (2002AJ....123.2945R 2002AJ....123.2945R)
402-408 F7.3 mas/yr pm [0.005/193]? Proper motion
in milliarcseconds per year
410 I1 --- DB [1/7] Bitwise flag indicating low-z (20),
mid-z (21), and high-z (22) sources
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Note (1): 32 are known compact emission-line galaxies (CELGs),
5 have spectra that are difficult to classify (given as "??" in the
catalog). See section 5.3 for further details.
Note (2): We match our optical catalog to near-IR catalogs from the regions of
sky covered by the UKIRT Infrared Deep Sky Survey (UKIDSS;
Lawrence et al. 2007, see II/319) and the Vista Hemisphere Survey
(VHS; McMahon 2012 Science from the Next Generation Imaging and
Spectroscopic Surveys (Garching: ESO)). We used a matching radius of
1" and included only objects that have measurements in each of
J, H, and K. See section 2.3.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 02-Oct-2015