J/ApJS/243/5 The ELQS in the PS1 footprint (PS-ELQS) (Schindler+, 2019)
The Extremely Luminous Quasar Survey in the Pan-STARRS 1 footprint (PS-ELQS).
Schindler J.-T., Fan X., Huang Y.-H., Yue M., Yang J., Hall P.B., Wenzl L.,
Hughes A., Litke K.C., Rees J.M.
<Astrophys. J. Suppl. Ser., 243, 5-5 (2019)>
=2019ApJS..243....5S 2019ApJS..243....5S (SIMBAD/NED BibCode)
ADC_Keywords: QSOs; Redshifts; Photometry, ugriz; Photometry, ultraviolet;
Spectra, optical; X-ray sources; Surveys
Keywords: galaxies: nuclei; quasars: general
Abstract:
We present the results of the Extremely Luminous Quasar Survey in the
3π survey of the Panoramic Survey Telescope and Rapid Response
System (Pan-STARRS; PS1). This effort applies the successful quasar
selection strategy of the Extremely Luminous Survey in the Sloan
Digital Sky Survey footprint (∼12000deg2) to a much larger area
(∼21486deg2). This spectroscopic survey targets the most luminous
quasars (M1450≤-26.5; mi≤18.5) at intermediate redshifts
(z≥2.8). Candidates are selected based on a near-infrared JKW2 color
cut using WISE AllWISE and 2MASS photometry to mainly reject stellar
contaminants. Photometric redshifts (zreg) and star-quasar
classifications for each candidate are calculated from near-infrared
and optical photometry using the supervised machine learning technique
random forests. We select 806 quasar candidates at zreg≥2.8 from a
parent sample of 74318 sources. After exclusion of known sources and
rejection of candidates with unreliable photometry, we have taken
optical identification spectra for 290 of our 334 good PS-ELQS
candidates. We report the discovery of 190 new z≥2.8 quasars and an
additional 28 quasars at lower redshifts. A total of 44 good PS-ELQS
candidates remain unobserved. Including all known quasars at z≥2.8,
our quasar selection method has a selection efficiency of at least
77%. At lower declinations, -30≤DEC≤0, we approximately treble the
known population of extremely luminous quasars. We provide the PS-ELQS
quasar catalog with a total of 592 luminous quasars (mi≤18.5,
z≥2.8). This unique sample will not only be able to provide
constraints on the volume density and quasar clustering of extremely
luminous quasars, but also offers valuable targets for studies of the
intergalactic medium.
Description:
Dedicated observational campaigns for the Extremely Luminous Quasar
Survey in the Pan-STARRS 1 Footprint (PS-ELQS) began in fall 2017
after the candidate selection was frozen in. Observations were
completed in 2018 June.
The majority of our observations were carried out with the Goodman
High Throughput Spectrograph (Goodman HTS) on the Southern
Astrophysical Research (SOAR) Telescope (4.1m). Spectra were taken in
2017 October 6-10, 2018 January 22-24, 2018 April 4-6, and 2018 June
2-4. The spectra have a wavelength coverage of ∼4000-8000 and
∼5300-9300Å for the two different central wavelengths; resulting in
spectral resolutions of R∼830 and R∼690, respectively.
Identification spectroscopy in the northern hemisphere was carried out
with the VATTSpec spectrograph on the Vatican Advanced Technology
Telescope (VATT). Targeted PS-ELQS observations were conducted in 2017
November 7-12, 2018 March 19-21, and 2018 May 17-18; with a resolution
of R∼1000.
We followed up our newly discovered quasars with the Red Channel
Spectrograph on the MMT. Observations were taken in 2017 October 20-21,
2017 November 16, and 2018 May 14; with a resolution of R∼400 to 300.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table7.dat 451 592 Full Pan-STARRS 1 Extremely Luminous Quasar Survey
(PS-ELQS) quasar catalog
table8.dat 98 190 Newly discovered quasars at z≥2.8 in
the PS-ELQS sample
table9.dat 98 28 Newly discovered quasars at z<2.8 in
the PS-ELQS sample
table10.dat 59 44 Properties of the remaining good PS-ELQS candidates
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+, 2003)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
VII/269 : SDSS Quasar Catalog, DR9Q (Paris+, 2012)
II/328 : AllWISE Data Release (Cutri+, 2013)
VII/273 : The Half Million Quasars (HMQ) catalogue (Flesch, 2015)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
VII/279 : SDSS quasar catalog: twelfth data release (Paris+, 2017)
II/335 : Revised cat. of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
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/133/2222 : Clustering of high-redshift QSOs from SDSS (Shen+, 2007)
J/MNRAS/406/1583 : Quasar from SDSS and UKIDSS (Wu+, 2010)
J/ApJ/728/23 : GALEX UV-bright high-redshift quasars (Worseck+, 2011)
J/MNRAS/414/2602 : Automated classification of HIP variables (Dubath+, 2011)
J/AJ/144/49 : Quasars from SDSS-DR7, WISE and UKIDSS surveys (Wu+, 2012)
J/ApJ/768/105 : QSO luminosity function from SDSS Stripe 82 (McGreer+, 2013)
J/ApJ/773/14 : BOSS: quasar luminosity function (Ross+, 2013)
J/ApJS/219/39 : QSOs selection from SDSS and WISE (Richards+, 2015)
J/A+A/584/A44 : Photometric classification of QSO from RCS-2 (Carrasco+, 2015)
J/A+A/588/A103 : 2nd ROSAT all-sky survey (2RXS) source catalog (Boller+, 2016)
J/ApJS/227/11 : PS1 z>5.6 quasars follow-up (Banados+, 2016)
J/MNRAS/473/4937 : AllWISE ctp to ROSAT/2RXS+XMMSLEW2 catalogs (Salvato+, 2018)
J/ApJ/863/144 : ELQS in SDSS footprint. II. North Gal. Cap (Schindler+, 2018)
Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- WISEA WISE AllWISE survey designation
(JHHMMSS.ss+DDMMSS.s)
21- 32 F12.8 deg RAdeg PS1 Right Ascension, decimal degrees (J2000)
34- 45 F12.8 deg DEdeg PS1 Declination, decimal degrees (J2000)
47- 48 I2 h RAPh PS1 Hour of Right Ascension (J2000)
50- 51 I2 min RAPm PS1 Minute of Right Ascension (J2000)
53- 58 F6.3 s RAPs PS1 Second of Right Ascension (J2000)
60- 60 A1 --- DEP- PS1 Sign of the Declination (J2000)
61- 62 I2 deg DEPd PS1 Degree of Declination (J2000)
64- 65 I2 arcmin DEPm PS1 Arcminute of Declination (J2000)
67- 71 F5.2 arcsec DEPs PS1 Arcsecond of Declination (J2000)
73- 83 F11.7 deg RAAdeg ALLWISE Right Ascension (J2000)
85- 95 F11.7 deg DEAdeg ALLWISE Declination (J2000)
97-106 A10 --- Ref Reference, quasar classification (1)
108-112 F5.3 --- z [2.8/5.1] Best redshift of the quasar,
from Ref
114-120 F7.3 mag 1450Mag [-30.7/-26.7] Absolute magnitude,
1450Å (G1)
122-127 F6.3 mag gmag [16.3/22.2] Dereddened AB magnitude,
PS1 g band
129-134 F6.3 mag rmag Dereddened AB magnitude, PS1 r band
136-141 F6.3 mag imag Dereddened AB magnitude, PS1 i band
143-148 F6.3 mag zmag Dereddened AB magnitude, PS1 z band
150-155 F6.3 mag ymag Dereddened AB magnitude, PS1 y band
157-162 F6.3 mag Jmag [14.2/18.4] Dereddened AB magnitude,
2MASS J band
164-169 F6.3 mag Hmag Dereddened AB magnitude, 2MASS H band
171-176 F6.3 mag Ksmag Dereddened AB magnitude, 2MASS Ks band
178-183 F6.3 mag W1mag [13.7/18.4] Dereddened AB magnitude,
WISE W1 band
185-190 F6.3 mag W2mag Dereddened AB magnitude, WISE W2 band
192-199 F8.6 mag e_gmag [0.002/0.1] 1σ uncertainty in gmag
201-208 F8.6 mag e_rmag 1σ uncertainty in rmag
210-217 F8.6 mag e_imag 1σ uncertainty in imag
219-226 F8.6 mag e_zmag 1σ uncertainty in zmag
228-235 F8.6 mag e_ymag 1σ uncertainty in ymag
237-241 F5.3 mag e_Jmag [0.02/0.3]? 1σ uncertainty in Jmag
243-247 F5.3 mag e_Hmag ? 1σ uncertainty in Hmag
249-253 F5.3 mag e_Ksmag ? 1σ uncertainty in Ksmag
255-259 F5.3 mag e_W1mag [0.02/0.3] 1σ uncertainty in W1mag
261-265 F5.3 mag e_W2mag 1σ uncertainty in W2mag
267-275 F9.7 mag E(B-V) [0.006/1] E(B-V) color excess
277-281 A5 --- GALEX Boolean, successful match with GALEX GR6/7
283-289 F7.5 arcsec SepG [0.19/1.8]? Match distance,
GALEX GR6/7 to SDSS
291-298 F8.3 mag NUVmag [19.6/23.8]? GALEX near-UV magnitude (G2)
300-310 F11.6 mag e_NUVmag [0.01/0.6]? Error on NUVmag
312-319 F8.3 mag FUVmag [20.5/23.5]? GALEX far-UV magnitude (G2)
321-331 F11.6 mag e_FUVmag [0.03/0.7]? Error on FUVmag
333-337 A5 --- TRXS Boolean, successful match with
ROSAT 2RXS AllWISE
339-348 E10.4 arcsec SepT [0/5.6e-14]? Match distance, ELQS AllWISE
to ROSAT 2RXS AllWISE (2)
350-352 F3.1 --- f_TRXS [1/2]? TRXS-match flag (3)
354-363 E10.4 mW/m2 F2RXS [1.7e-13/3.7e-12]? 2RXS flux,
in erg/s/cm2 units
365-374 E10.4 mW/m2 e_F2RXS ? Error on F2RXS
376-380 A5 --- XMM Boolean, successful match with
XMMSL2 AllWISE
382-391 E10.4 arcsec SepX [0/3e-14]? Match distance, ELQS AllWISE to
XMMSL2 AllWISE
393-395 F3.1 --- f_XMM [1]? XMM-match flag (4)
397-405 F9.6 10-15W/m2 FB8 [0.6/13]? Total band (0.2-12.0keV) flux,
in 10-12erg/s/cm2 units
407-415 F9.6 10-15W/m2 FB7 [24.562504]? Hard band (2.0-12.0keV) flux,
in 10-12erg/s/cm2 units
417-424 F8.6 10-15W/m2 FB6 [0.2/2.3]? Soft band (0.2-2.0keV) flux,
in 10-12erg/s/cm2 units
426-433 F8.6 10-15W/m2 e_FB8 [0.3/4]? Error on FB8
435-442 F8.6 10-15W/m2 e_FB7 [8.582023]? Error on FB7
444-451 F8.6 10-15W/m2 e_FB6 [0.1/1]? Error on FB6
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Note (1): Reference, quasar classification as follows:
DR7Q = SDSS DR7; Schneider+ (2010, VII/260);
DR14Q = SDSS DR14; Paris et al. (2018A&A...613A..51P 2018A&A...613A..51P);
ELQS = Extremely Luminous Quasar Survey;
Schindler et al. (2017ApJ...851...13S 2017ApJ...851...13S);
MQ = Million Quasar Catalog, version 5.7b;
Flesch (2015PASA...32...10F 2015PASA...32...10F ; Cat. VII/273 see also VII/283);
PS-ELQS = this work;
other_qsos = Yang et al. (2019ApJ...871..199Y 2019ApJ...871..199Y).
Note (2): The distance values are often 0 or otherwise extremely small,
because the positions match to numerical accuracy.
Note (3): A flag indicating the most probable AllWISE ROSAT 2RXS cross-match
with 1. This is the case for all matched objects.
Note (4): A flag indicating the most probable AllWISE XMMSL2 cross-match
with 1. This is the case for all matched objects
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Byte-by-byte Description of file: table[89].dat
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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- 14 A1 --- DE- Sign of the 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- 32 F6.3 mag imag [16.4/18.5] Dereddened AB magnitude,
PS1 i band
34- 41 F8.6 mag e_imag [0/0.04] 1σ uncertainty in imag-PS
43- 49 F7.3 mag 1450Mag [-29.4/-22.3] Absolute magnitude, 1450Å (G1)
51- 55 F5.3 --- zspec [0.3/4.9] Spectroscopic redshift, this work
57- 62 F6.3 mag NUVmag [20.1/23]? GALEX near-UV magnitude (G2)
64- 70 F7.5 mag e_NUVmag [0.09/0.5]? Error on NUVmag
72- 77 F6.3 mag FUVmag [20.5/22.6]? GALEX far-UV magnitude (G2)
79- 85 F7.5 mag e_FUVmag [0.1/0.6]? Error on FUVmag
87- 96 A10 "Y/M/D" Date Observation date
98- 98 A1 --- Flag [cd] Flag (1)
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Note (1): Flag as follows:
c = This object has been classified as a BAL, LoBAL or FeLoBAL quasar.
Details are discussed in Section 7.2;
d = These objects were also independently discovered
by Yang+ (2019ApJ...871..199Y 2019ApJ...871..199Y).
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Byte-by-byte Description of file: table10.dat
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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 the 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- 32 F6.3 mag imag [17.2/18.5] Dereddened AB magnitude, PS1 i band
34- 41 F8.6 mag e_imag [0.002/0.02] 1σ uncertainty in imag-PS
43- 46 F4.2 --- zphot [2.8/4.5] Photometric redshift
48- 51 F4.2 --- zprob [0.47/1] Random forest pseudo-probability of
being a quasars
53- 57 A5 --- zclass Most likely redshift class ("highz" or "midz")
59 I1 --- Prior [1/5] Priority (1)
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Note (1): PS-ELQS quasar candidates and their selection priorities
(see Table 5):
----------------------------------------------------
Priority Criteria
----------------------------------------------------
1 3.5≤zreg and mi≤18.0
2 3.0≤zreg≤3.5 and mi≤18.0
3 (2.5≤zreg≤3.0 and mi≤18.0)
OR (3.5≤zreg and 18.0<mi≤18.5)
4 3.0≤zreg≤3.5 and 18.0<mi≤18.5
5 2.5≤zreg≤3.0 and 18.0<mi≤18.5
----------------------------------------------------
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Global notes:
Note (G1): Absolute magnitude at 1450Å calculated using the k-correction
determined for this work.
Note (G2): The near and far UV magnitudes were obtained from cross-matches
within 2 arcsec to the GALEX GR6/7 data release.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Dec-2019