J/MNRAS/477/L70 Strongly lensed quasars in SDSS (Williams+, 2018)
Discovery of three strongly lensed quasars in the Sloan Digital Sky Survey.
Williams P.R., Agnello A., Treu T., Abramson L.E., Anguita T.,
Apostolovski Y., Chen G.C.-F., Fassnacht C.D., Hsueh J.W., Lemaux B.C.,
Motta V., Oldham L., Rojas K., Rusu C.E., Shajib A.J., Wang X.
<Mon. Not. R. Astron. Soc., 477, L70-L74 (2018)>
=2018MNRAS.477L..70W 2018MNRAS.477L..70W (SIMBAD/NED BibCode)
ADC_Keywords: Gravitational lensing ; Redshifts
Keywords: gravitational lensing: strong - methods: observational
Abstract:
We present the discovery of three quasar lenses in the Sloan Digital
Sky Survey, selected using two novel photometry-based selection
techniques. The J0941+0518 system, with two point sources separated by
5.46 arcsec on either side of a galaxy, has source and lens redshifts
1.54 and 0.343. Images of J2257+2349 show two point sources separated
by 1.67 arcsec on either side of an E/S0 galaxy. The extracted spectra
show two images of the same quasar at zs=2.10. SDSS J1640+1045 has
two quasar spectra at zs=1.70 and fits to the SDSS and Pan-STARRS
images confirm the presence of a galaxy between the two point sources.
We observed 56 photometrically selected lens candidates in this
follow-up campaign, confirming three new lenses, re-discovering one
known lens, and ruling out 36 candidates, with 16 still inconclusive.
This initial campaign demonstrates the power of purely photometric
selection techniques in finding lensed quasars.
Description:
Candidates were observed using the Near-Infrared Camera 2 (NIRC2), the
Echellette Spectrograph and Imager (ESI), the OH-Suppressing InfraRed
Imaging Spectrograph (OSIRIS), and the DEep Imaging Multi-Object
Spectrograph (DEIMOS) at Keck Observatory; the ESO Faint Object
Spectrograph and Camera (EFOSC2) at the New Technology Telescope; and
the Adaptive Optics Module and Goodman Spectrograph at the Southern
Astrophysical Research Telescope. In this campaign, we observed 56
total candidates (Table 1), including three new lenses and one known
lens.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 178 56 List of all observed candidates along with their
selection method, observing outcome, and
lens and source redshift, if available
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Name (JHHMM+DDMM)
12- 22 F11.7 deg RAdeg Right ascension (J2000)
24- 34 F11.7 deg DEdeg Declination (J2000)
36- 40 F5.2 mag imag i magnitude
42- 46 F5.2 mag imag2 ? Second value of i magnitude
48- 52 F5.2 mag imag3 ? Third value of i magnitude
54- 71 A18 --- SelMode Selection method
73- 95 A23 --- Inst Instrument
97-140 A44 --- Com Comments
142-145 F4.2 --- zs ? Source redshift
147-151 F5.3 --- zl ? Lens redshift
152 A1 --- u_zl [?] Uncertainty flag on zl
154-178 A25 --- Outcome Observing outcome
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-May-2021