J/ApJ/921/42 Gaia GraL. VI. Quadruply imaged lensed QSOs (Stern+, 2021)
Gaia GraL: Gaia DR2 Gravitational Lens systems.
VI. Spectroscopic confirmation and modeling of quadruply imaged lensed quasars.
Stern D., Djorgovski S.G., Krone-Martins A., Sluse D., Delchambre L.,
Ducourant C., Teixeira R., Surdej J., Boehm C., den Brok J., Dobie D.,
Drake A., Galluccio L., Graham M.J., Jalan P., Kluter J.,
Le Campion J.-F., Mahabal A., Mignard F., Murphy T., Nierenberg A.,
Scarano S. Jr,Simon J.,Slezak E.,Spindola-Duarte C.,Wambsganss J.
<Astrophys. J., 921, 42 (2021)>
=2021ApJ...921...42S 2021ApJ...921...42S
ADC_Keywords: Gravitational lensing; QSOs; Spectra, optical; Redshifts
Keywords: Strong gravitational lensing ; Quasars
Abstract:
Combining the exquisite angular resolution of Gaia with optical light
curves and WISE photometry, the Gaia Gravitational Lenses group (GraL)
uses machine-learning techniques to identify candidate strongly lensed
quasars, and has confirmed over two dozen new strongly lensed quasars
from the Gaia Data Release 2. This paper reports on the 12 quadruply
imaged quasars identified by this effort to date, which is a ∼20%
increase in the total number of confirmed quadruply imaged quasars. We
discuss the candidate selection, spectroscopic follow-up, and lens
modeling. We also report our spectroscopic failures as an aid for
future investigations.
Description:
Spectroscopic follow-up for the Gaia Gravitational Lenses group (GraL)
program began in 2018 May and has used the Keck I Telescope atop
Maunakea, Hawaii, the 200" Hale Telescope at Palomar Observatory,
California, the 3.6m New Technology Telescope (NTT) at La Silla,
Chile, and the Gemini-South telescope at Cerro Pachon, Chile.
20 GraL observing nights with at least one GraL spectrum were obtained
between 2018 May 13 and 2020 Jun 20.
The primary instrument for GraL spectroscopic follow-up has been the
Low Resolution Imaging Spectrometer (LRIS) on the Keck I telescope,
used for 13 of the 20 GraL nights. Our LRIS instrument configuration
covers the full optical window at moderate resolving power, R∼1000 for
the 1.5" slit and R∼1500 for the 1.0" slit (for objects filling the
slit).
Several lens candidates were observed with the Palomar Double
Spectrograph (DBSP) in 2018 August. None of the confirmed quadruply
imaged quasars were observed with Palomar, though two doubly imaged
quasars in Krone-Martins+ (2019arXiv191208977K 2019arXiv191208977K ; Paper V) were
confirmed on these runs, and several of the GraL lens candidates were
invalidated at Palomar. This instrument configuration covers the full
optical window at moderate resolving power, R∼1250.
We used the ESO Faint Object Spectrograph and Camera (v.2; EFOSC2) on
the NTT on the nights of UT 2019 April 7-9 (PI: Ducourant;
Program ID 0103.A-0077). See Section 3.3.
Seven candidates were observed in queue-mode using the Gemini-South
Multi-Object Spectrograph (GMOS) in integral field unit (IFU) mode
(PI: Teixeira; Program ID GS-2019A-Q-104). We used the
lowest-resolution grating which covered the 7000-8200Å spectral
range with a resolving power R∼2000.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 206 25 *Confirmed GraL quad lenses
table6.dat 101 149 Invalidated GraL lens candidates (i.e., asterisms)
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Note on table2.dat: In addition to these 12 quadruply imaged lensed quasars,
we also confirm the doubly imaged lensed quasar GraL J201454.2-302452
(see Section 5).
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See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
VII/273 : The Half Million Quasars (HMQ) catalogue (Flesch, 2015)
VII/277 : The Million Quasars (Milliquas) catalog (Flesch, 2016)
VII/290 : The Million Quasars (Milliquas) catalogue, version 7.2 (Flesch, 2021)
J/ApJ/651/61 : Opt. thick absorbers near luminous quasars (Hennawi+, 2006)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/ApJ/775/116 : z<0.06 active BH galaxies from SDSS-DR8 (Reines+, 2013)
J/ApJ/798/95 : HE1104-1805 BVRIJ light curves (Blackburne+, 2015)
J/ApJS/234/23 : The WISE AGN candidates catalogs (Assef+, 2018)
J/A+A/618/A56 : Gaia GraL. II. Known multiply imaged QSOs (Ducourant+, 2018)
J/A+A/622/A165 : Gaia GraL. III. New lensed systems (Delchambre+, 2019)
J/A+A/632/A56 : KiDS-BEXGO catalog (Khramtsov+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [GraL]
6- 21 A16 --- GraL GraL identifier (JHHMMSS.s+DDMMSS)
23- 26 F4.1 arcmin Sep [0.7/10.1]? Maximum lens separation (1)
28- 32 A5 --- Night Observation night code (G1)
34- 36 I3 deg PA [-10/352] Position angle
38- 42 A5 s Exp Exposure time
44- 48 F5.3 --- z [0.77/3.1]? Spectroscopic redsfhit
50-206 A157 --- Notes Notes
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Note (1): The maximum lens separations are based on the astrometry provided
in Table 5 in the Appendix; these values, primarily coming from Gaia,
are also reported in the text of Section 4.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- GraL GraL position-based identifier (JHHMM+DDMM)
20- 21 I2 h RAh Hour of Right Ascension (J2000)
23- 24 I2 min RAm Minute of Right Ascension (J2000)
26- 27 I2 s RAs Second of Right Ascension (J2000)
29- 29 A1 --- DE- Sign of the Declination (J2000)
30- 31 I2 deg DEd Degree of Declination (J2000)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 37 I2 arcsec DEs Arcsecond of Declination (J2000)
39- 43 A5 --- Night Observation night code (G1)
45- 47 I3 deg PA [0/356] Position Angle
49- 59 A11 s Exp Exposure Time
61-101 A41 --- Notes Notes
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Global notes:
Note (G1): List of observing nights:
------------------------------------------------------------------------
UT date Code Instrument Conditions/Notes
------------------------------------------------------------------------
2018 May 13 N01-K Keck/LRIS photometric
2018 Jun 16 N02-K Keck/LRIS cirrus, poor seeing
2018 Jul 16 N03-K Keck/LRIS clear, lost 4hr to elec. prob.
2018 Aug 18 N04-P Palomar/DBSP clouds
2018 Aug 20 N05-P Palomar/DBSP clear, 1.0" seeing
2018 Sep 15 N06-K Keck/LRIS light cirrus, 1.0" seeing
2018 Oct 03 N07-K Keck/LRIS clear, 0.65" seeing
2019 Jan 12 N08-K Keck/LRIS clear, good seeing
2019 Feb 06 N09-K Keck/LRIS clear, good seeing
2019 Apr 07 N10-G Gemini-S/GMOS queue; clear, 0.5" seeing
2019 Apr 07 N11-N NTT/EFOSC2 clear, 0.7" seeing
2019 Apr 08 N12-N NTT/EFOSC2 clear, 0.8" seeing
2019 Apr 09 N13-N NTT/EFOSC2 clear, 1.0" seeing
2019 May 01 N14-P Palomar/DBSP lost to clouds
2019 Jun 01 N15-K Keck/LRIS clear
2019 Jun 02 N16-K Keck/LRIS clear; half night
2019 Sep 19 N17-K Keck/LRIS cloudy
2019 Dec 04 N18-K Keck/LRIS cirrus, 0.7" seeing; half night
2020 Jan 26 N19-K Keck/LRIS clear, 0.75" seeing
2020 Jun 20 N20-K Keck/LRIS scattered cirrus, good seeing
------------------------------------------------------------------------
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Nomenclature Notes:
QSOs are <[SDK2021] GraL JHHMMSS.s+DDMMSS source> in Simbad ; whereas
<[SDK2021] GraL JHHMMSS.s+DDMMSS> in Simbad are the Gravitational Lens
System (lens+images).
History:
From electronic version of the journal
References:
Krone-Martins et al. Paper I. 2018A&A...616L..11K 2018A&A...616L..11K
Ducourant et al. Paper II. 2018A&A...618A..56D 2018A&A...618A..56D Cat. J/A+A/618/A56
Delchambre et al. Paper III. 2019A&A...622A.165D 2019A&A...622A.165D Cat. J/A+A/622/A165
Wertz et al. Paper IV. 2019A&A...628A..17W 2019A&A...628A..17W
Krone-Martins et al. Paper V. 2019arXiv191208977K 2019arXiv191208977K
Stern et al. Paper VI. 2021ApJ...921...42S 2021ApJ...921...42S This catalog
Connor et al. Paper VII. 2022ApJ...927...45C 2022ApJ...927...45C
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Feb-2023