J/ApJ/871/258 ELQS in SDSS. III. The full ELQS quasar catalog (Schindler+, 2019)
The Extremely Luminous Quasar Survey in the Sloan Digital Sky Survey footprint.
III. The South Galactic Cap sample and the quasar luminosity function at cosmic
noon.
Schindler J.-T., Fan X., McGreer I.D., Yang J., Wang F., Green R.,
Fynbo J.P.U., Krogager J.-K., Green E.M., Huang Y.-H., Kadowaki J.,
Patej A., Wu Y.-L., Yue M.
<Astrophys. J., 871, 258 (2019)>
=2019ApJ...871..258S 2019ApJ...871..258S
ADC_Keywords: QSOs; Redshifts; Spectra, optical; Photometry, SDSS;
Photometry, ultraviolet; Photometry, infrared; Surveys;
Radio sources; X-ray sources
Keywords: galaxies: active ; galaxies: high-redshift ; galaxies: nuclei ;
quasars: general
Abstract:
We have designed the Extremely Luminous Quasar Survey (ELQS) to
provide a highly complete census of unobscured UV-bright quasars
during the cosmic noon, z=2.8-5.0. Here we report the discovery of 70
new quasars in the ELQS South Galactic Cap (ELQS-S) quasar sample,
doubling the number of known extremely luminous quasars in
4237.3deg2 of the Sloan Digital Sky Survey footprint. These
observations conclude the ELQS and we present the properties of the
full ELQS quasar catalog, containing 407 quasars over 11838.5deg2.
Our novel ELQS quasar selection strategy resulted in unprecedented
completeness at the bright end and allowed us to discover 109 new
quasars in total. This marks an increase of ∼36% (109/298) in the
known population at these redshifts and magnitudes, while we further
are able to retain a selection efficiency of ∼80%. On the basis of 166
quasars from the full ELQS quasar catalog, which adhere to the uniform
criteria of the Two Micron All Sky Survey point source catalog, we
measure the bright-end quasar luminosity function (QLF) and extend it
one magnitude brighter than previous studies. Assuming a single power
law with exponential density evolution for the functional form of the
QLF, we retrieve the best-fit parameters from a maximum likelihood
analysis. We find a steep bright-end slope of β~-4.1, and we can
constrain the bright-end slope to β≤-3.4 with 99% confidence.
The density is well modeled by the exponential redshift evolution,
resulting in a moderate decrease with redshift (γ~-0.4).
Description:
This work presents the final Extremely Luminous Quasar Survey (ELQS)
quasar catalog, covering the entire SDSS footprint
(11838.5±20.1deg2), and the resulting quasar luminosity function
(QLF) at the bright end at redshifts 2.8≤z≤4.5.
We also report the results of our spectroscopic identification
campaign in the South Galactic Cap, the ELQS-S sample.
Observations of the ELQS-S sample have been completed and 96 out of 97
candidates were observed with a range of different telescopes. These
include the Vatican Advanced Technology Telescope (VATT; R∼1000;
central wavelength of ∼5775Å), the MMT 6.5m telescope (R∼300-400;
central wavelenghts of 6400, 7000, 7150Å or 5000, 5500, 6083Å
or 3705, 3310Å according to the gratings), the 90 inch (2.3m) Bok
Telescope (R∼750; ∼3655-6850Å), the Nordic Optical Telescope (NOT;
wavelength coverage of 3200-9600Å for R∼360 and R∼280), and the
(4.1m) Southern Astrophysical Research Telescope (SOAR; R∼830 and
R∼690 for a spectral coverage of ∼4000-8000Å and ∼5300-9300Å).
Pilot observations with the VATTSpec spectrograph on the VATT started
on 2015 October 8-12. The program continued on 2016 November 20-23
and December 18-20. In 2017 we finished the South Galactic Cap
footprint during observations on November 7-12. Depending on the
object and the conditions, the exposure times varied between 15 and 30min.
The Boller & Chivens Spectrograph observations on the Bok telescope
were conducted in 2016 on October 13-14 and November 15. We used
exposure times of ∼5-15 minutes.
The Multiple Mirror Telescope (MMT) Red Channel Spectrograph
observations were taken in 2017 on May 17-18, October 20-21, and
November 16 and on 2018 January 20. We chose exposure times of ∼3-15
minutes per spectrum.
In 2017, some identification spectra were taken during the Nordic
Optical Telescope (NOT) summer schools (August 23-25, September 5-9).
These observations were conducted with the Andalucia Faint Object
Spectrograph and Camera (ALFOSC). Exposure times varied between 2.5
and 5 minutes.
In addition, we observed quasar candidates with the Goodman High
Throughput Spectrograph (Goodman HTS) on the Southern Astrophysical
Research Telescope (SOAR) (4.1m). These observations were carried out
on 2017 October 6-10 and 2018 January 22-24. Exposure times varied
between 3 and 15 minutes.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 87 70 Newly discovered quasars at z≥2.8 in the ELQS-S sample
elqs.dat 611 407 The full Extremely Luminous Quasar Survey (ELQS)
quasar catalog
table10.dat 71 18 Newly discovered quasars at z<2.8 in the ELQS sample
table11.dat 62 51 Newly discovered quasars not part of the ELQS primary
candidate catalog
--------------------------------------------------------------------------------
See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
VII/273 : The Half Million Quasars (HMQ) catalogue (Flesch, 2015)
II/335 : Revised catalog GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
VII/286 : SDSS quasar catalog, fourteenth data release (Paris+, 2018)
VII/283 : The Million Quasars (Milliquas) catalog (6.3) (Flesch, 2019)
J/ApJ/635/123 : The SDSS-DR3 damped Lyα survey (Prochaska+, 2005)
J/AJ/131/2766 : Quasar luminosity function from SDSS-DR3 (Richards+, 2006)
J/AJ/131/2788 : Redshifts in the SFQS survey (Jiang+, 2006)
J/ApJS/165/1 : BAL QSOs from SDSS DR3 (Trump+, 2006)
J/MNRAS/386/1605 : Luminous K-band selected QSOs from UKIDSS (Maddox+, 2008)
J/MNRAS/406/1583 : Quasar from SDSS and UKIDSS (Wu+, 2010)
J/MNRAS/410/860 : Redshift dependence of BAL QSOs (Allen+, 2011)
J/ApJ/728/23 : GALEX UV-bright high-redshift quasars (Worseck+, 2011)
J/AJ/143/119 : SDSS Quasar Lens Search. V. Final catalog (Inada+, 2012)
J/ApJ/755/169 : 3<z<5 quasar luminosity function in COSMOS (Masters+, 2012)
J/AJ/144/49 : Quasars from SDSS-DR7, WISE and UKIDSS surveys (Wu+, 2012)
J/ApJS/199/3 : The quasars MMT-BOSS pilot survey (Ross+, 2012)
J/ApJ/768/105 : z∼5 QSO lum. function from SDSS Stripe 82 (McGreer+, 2013)
J/ApJ/773/14 : BOSS: quasar luminosity function (Ross+, 2013)
J/A+A/588/A103 : Second ROSAT all-sky survey (2RXS) catalog (Boller+, 2016)
J/ApJ/819/24 : z>4.5 QSOs with SDSS and WISE. I. Opt. spectra (Wang+, 2016)
J/ApJ/829/33 : Luminous of high-z QSOs with SDSS and WISE. II (Yang+, 2016)
J/ApJ/847/81 : HeII photoionization rates of quasars (Schmidt+, 2017)
J/AJ/155/189 : LAMOST Quasar Survey: quasar properties DR2&3 (Dong+, 2018)
J/AJ/155/131 : z∼5 quasar luminosity function from CFHTLS (McGreer+, 2018)
J/MNRAS/473/4937 : AllWISE ctp to ROSAT/2RXS & XMMSLEW2 cat. (Salvato+, 2018)
J/ApJ/863/144 : ELQS in SDSS footprint. II. North Gal. Cap (Schindler+,2018)
http://skyserver.sdss.org/dr13/ : SDSS DR13 homepage
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Hour of right ascension (J2000)
4- 5 I2 min RAm Minute of right ascension (J2000)
7- 12 F6.3 s RAs Second of right ascension (J2000)
14 A1 --- DE- Sign of declination (J2000)
15- 16 I2 deg DEd Degree of declination (J2000)
18- 19 I2 arcmin DEm Arcminute of declination (J2000)
21- 25 F5.2 arcsec DEs Arcsecond of declination (J2000)
27- 31 F5.2 mag imag [16/18] SDSS i band dereddened AB magnitude
33- 36 F4.2 mag e_imag [0.01/0.07] Error on imag
38- 43 F6.2 mag M1450 [-29.5/-27.1] Absolute magnitude at 1450Å
45- 49 F5.3 --- z [2.8/4.3] Spectroscopique redshift
51- 55 F5.2 mag NUVmag [20/21.6]? GALEX near-UV magnitude (1)
57- 60 F4.2 mag e_NUVmag [0.04/0.2]? Error on NUVmag
62- 66 F5.2 mag FUVmag [21/24]? GALEX far-UV magnitude (1)
68- 71 F4.2 mag e_FUVmag [0.1/0.5]? Error on FUVmag
73- 74 I2 --- BAL [-1/1]? Visual qualitative Broad Absorption
Line (BAL) identification flag (2)
76- 85 A10 "date" Date UT date of observation
87 A1 --- f_Date Flag on Date (3)
--------------------------------------------------------------------------------
Note (1): The near and far-UV magnitudes were obtained from cross-matches within
2.0" to the GALEX GR6/7 data release.
Note (2): Flags as follows:
-1 = insufficient wavelength coverage or inconclusive archival data
(5 occurrences)
0 = no BAL (54 occurrences)
1 = BAL (11 occurrences)
Note (3): Flags as follows:
a = See also HST GO Proposal 13013 (PI: Gabor Worseck),
Zheng+, (2015ApJ...806..142Z 2015ApJ...806..142Z ), and Schmidt+, (2017, J/ApJ/847/81).
b = These objects were also independently discovered by
Yang+, (2016, J/ApJ/829/33)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: elqs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- WISEA AllWISE survey designation
(JHHMMSS.ss+DDMMSS)
21- 36 F16.12 deg RASdeg [0.9/360] SDSS DR13 right ascension (J2000)
38- 56 F19.15 deg DESdeg [-22/79] SDSS DR13 declination (J2000)
58- 59 I2 h RAh SDSS DR13 hour of right ascension (J2000)
61- 62 I2 min RAm SDSS DR13 minute of right ascension (J2000)
64- 69 F6.3 s RAs SDSS DR13 second of right ascension (J2000)
71- 71 A1 --- DE- Sign of the SDSS DR13 declination (J2000)
72- 73 I2 deg DEd SDSS DR13 degree of declination (J2000)
75- 76 I2 arcmin DEm SDSS DR13 arcminute of declination (J2000)
78- 82 F5.2 arcsec DEs SDSS DR13 arcsecond of declination (J2000)
84- 94 F11.7 deg RAWdeg [0.9/360] AllWISE right ascension (J2000)
96-106 F11.7 deg DEWdeg [-22/79] AllWISE declination (J2000)
108-117 A10 --- Ref Reference to quasar classification (1)
119-129 F11.9 --- z [2.8/4.7] Best redshift of quasar
according to the reference
131-144 F14.10 mag M1450 [-31/-27.1] Absolute magnitude at 1450Å
calculated using the k-correction
determined in this work
146-160 F15.13 --- Prob [0/1] Selection probability
according to our completeness calculation
(see Section 5.2 in Paper II;
Schindler+, 2018, J/ApJ/863/144)
162-172 F11.8 mag umag [17.7/26.4] SDSS PSF u band dereddened AB
magnitude (SDSS Asinh system)
174-184 F11.8 mag gmag [16.4/20.7] SDSS PSF g band dereddened AB
magnitude (SDSS Asinh system)
186-197 F12.9 mag rmag [15.3/19] SDSS PSF r band dereddened AB
magnitude (SDSS Asinh system)
199-209 F11.8 mag imag [14.8/18] SDSS PSF i band dereddened AB
magnitude (SDSS Asinh system)
211-222 F12.9 mag zmag [14.5/18.1] SDSS PSF z band dereddened AB
magnitude (SDSS Asinh system)
224-236 F13.10 mag Jmag [14.2/18.2] 2MASS J band dereddened AB
magnitude
238-250 F13.10 mag Hmag [14/19.1] 2MASS h band dereddened AB
magnitude
252-264 F13.10 mag Ksmag [13.8/18.4] 2MASS Ks band dereddened AB
magnitude
266-278 F13.10 mag W1mag [13.7/18.2] WISE 3.4um band dereddened AB
magnitude
280-292 F13.10 mag W2mag [13.8/18.2] WISE 4.6um band dereddened AB
magnitude
294-303 F10.8 mag e_umag [0.01/3.7] 1σ uncertainty in umag
305-315 F11.9 mag e_gmag [0.008/0.3] 1σ uncertainty in gmag
317-327 F11.9 mag e_imag [0.006/0.1] 1σ uncertainty in imag
329-339 F11.9 mag e_rmag [0.008/0.2] 1σ uncertainty in rmag
341-350 F10.8 mag e_zmag [0.01/0.2] 1σ uncertainty in zmag
352-356 F5.3 mag e_Jmag [0.02/0.3] 1σ uncertainty in Jmag
358-362 F5.3 mag e_Hmag [0.02/0.4]? 1σ uncertainty in Hmag
364-368 F5.3 mag e_Ksmag [0.02/0.4]? 1σ uncertainty in Ksmag
370-374 F5.3 mag e_W1mag [0.02/0.2] 1σ uncertainty in W1mag
376-380 F5.3 mag e_W2mag [0.02/0.2] 1σ uncertainty in W2mag
382-397 F16.14 mag E(B-V) [0.006/0.7]? The (B-V) color excess
399-408 F10.8 mag Ai [0.006/1.2] Extinction in SDSS i band
410-414 A5 --- FIRST [True False] Successful match with FIRST
catalog
416-432 E17.11 arcsec SepRad [1.6e-05/5.6e-04]? FIRST/SDSS position
offset
434-440 F7.2 mJy/beam F1.4GHz [1/2405]? FIRST 1.4GHz peak flux
442-446 F5.3 mJy/beam e_F1.4GHz [0.1/0.6]? RMS error in F1.4GHz
448-452 A5 --- GALEX [True False] Successful match with GALEX
GR6/7 catalog?
454-468 F15.13 arcsec SepUV [0.09/1.8]? GALEX/SDSS position offset
470-484 F15.10 mag NUVmag [19.6/23.8]? GALEX near-UV band magnitude
486-503 F18.13 mag e_NUVmag [0.01/0.7]? Uncertainty in NUVmag
505-519 F15.10 mag FUVmag [20.5/24]? GALEX far-UV band magnitude
521-538 F18.13 mag e_FUVmag [0.03/0.6]? Uncertainty in FUVmag
540-544 A5 --- 2RXS [True False] Successful match with ROSAT
2RXS catalog?
546-562 E17.11 arcsec SepX [0/2.8e-14]? ROSAT/AllWISE position offset
564-566 F3.1 --- f_2RXS [1]? Most probable AllWISE ROSAT 2RXS
cross-match; 1.0
568-584 E17.10 mW/m2 FX [1.73e-13/1.07e-12]? ROSAT 2RXS flux;
in erg/s/cm2 units
586-602 E17.10 mW/m2 e_FX [6.5e-14/3.6e-13]? Uncertainty in FX
604-605 I2 --- BAL [-1/1]? Broad Absorption Line flag (2)
607-611 A5 --- QLF [True False] Included in quasar luminosity
function? (see Section 6)
--------------------------------------------------------------------------------
Note (1): References as follows:
DR14Q = Paris+, 2018, VII/286 (239 occurrences)
DR7Q = Schneider+, 2010, VII/260 (1 occurrence)
ELQS = This work (109 occurrences)
LAMOST_DR3 = Dong+, 2018, J/AJ/155/189 (3 occurrences)
MQ = Flesch, 2019, VII/283 (31 occurrences)
SDSS_DR13 = SDSS D13 website (1 occurrence)
Yang = Yang+, 2016, J/ApJ/829/33 (23 occurrences)
Note (2): Flags as follows:
1 = BAL quasar (78 occurrences)
0 = quasar (305 occurrences)
-1 = no visual classification (24 occurrences)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh [0/17] Hour of right ascension (J2000)
4 -5 I2 min RAm Minute of right ascension (J2000)
7- 12 F6.3 s RAs Second f right ascension (J2000)
14 A1 --- DE- Sign of declination (J2000)
15- 16 I2 deg DEd Degree of declination (J2000)
18- 19 I2 arcmin DEm Arcminute of declination (J2000)
21- 25 F5.2 arcsec DEs Arcsecond of declination (J2000)
27- 31 F5.2 mag imag [16.7/18] SDSS i band dereddened
AB magnitude
33- 36 F4.2 mag e_imag [0.01/0.04] Error on imag
38- 43 F6.2 mag M1450 [-28.3/-26.1]? Absolute magnitude at 1450Å
45- 49 F5.3 --- z [1.5/2.8]? Spectroscopic redshift
51- 55 F5.2 mag NUVmag [21/22.6]? Near-UV magnitude
57- 60 F4.2 mag e_NUVmag [0.1/0.4]? Error on NUVmag
62- 71 A10 "date" Date UT date of observation
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table11.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Hour of right ascension (J2000)
4- 5 I2 min RAm Minute of right ascension (J2000)
7- 12 F6.3 s RAs Second of right ascension (J2000)
14 A1 --- DE- Sign of declination (J2000)
15- 16 I2 deg DEd Degree of declination (J2000)
18- 19 I2 arcmin DEm Arcminute of declination (J2000)
21- 25 F5.2 arcsec DEs Arcsecond of declination (J2000)
27- 31 F5.2 mag imag [16.94/18.43] SDSS i band dereddened
AB magnitude
33- 36 F4.2 mag e_imag [0.01/0.03] Error on imag
38- 43 F6.2 mag M1450 [-28.2/-25.8]? Absolute magnitude at 1450Å
45- 49 F5.3 --- z [1.9/4.2]? Spectroscopic redshift
51- 60 A10 "date" Date UT date of observation
62 A1 --- f_Date [a]? a: also independently discovered by
Yang+, 2016, J/ApJ/829/33
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Schindler J.-T. et al. Paper I. 2017ApJ...851...13S 2017ApJ...851...13S
Schindler J.-T. et al. Paper II. 2018ApJ...863..144S 2018ApJ...863..144S Cat. J/ApJ/863/144
(End) Prepared by [AAS], Coralie Fix [CDS], 09-Apr-2020