Gravitationally lensed quasars in Gaia: III. 22 new lensed quasars from Gaia Data Release 2

Abstract

We report the discovery and spectroscopic confirmation of 22 new gravitationally lensed quasars found using $\text{Gaia}$ data release 2. The selection was made using several techniques: multiple $\text{Gaia}$ detections around objects in quasar candidate catalogues, modelling of unWISE coadd pixels using $\text{Gaia}$ astrometry, and $\text{Gaia}$ detections offset from photometric and spectroscopic galaxies. Spectra of 33 candidates were obtained with the William Herschel Telescope, 22 of which are lensed quasars, 2 highly probably lensed quasars, 5 nearly identical quasar pairs, 1 inconclusive system, and 3 contaminants. Of the 3 confirmed quadruply imaged systems, J2145+6345 is a 2.1 arcsecond separation quad with 4 bright images ($G$=16.86, 17.26, 18.34, 18.56), making it ideal for time delay monitoring. Analysing this new sample alongside known lenses in the Pan-STARRS footprint, and comparing to expected numbers of lenses, we show that, as expected, we are biased towards systems with bright lensing galaxies and low source redshifts. We discuss possible techniques to remove this bias from future searches. A |b|>20 complete sample of lensed quasars detected by $\text{Gaia}$ and with image separations above 1 arcsecond will provide a valuable statistical sample of around 350 systems. Currently only 96 known lenses satisfy these criteria, yet promisingly, our unWISE modelling technique is able to recover all of these with simple WISE-$\text{Gaia}$ colour cuts that remove $\sim$80 per cent of previously followed-up contaminants. Finally, we provide an online database of known lenses, quasar pairs, and contaminant systems.

arXiv comment17 pages, 12 figures, accepted by MNRAS; https://www.ast.cam.ac.uk/ioa/research/lensedquasars/

References in corpus (64)

• emcee: The MCMC Hammer
• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Gaia mission
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• Spectroscopic Target Selection in the Sloan Digital Sky Survey: The Quasar Sample
• Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science
• The Pan-STARRS1 Surveys
• Gaia Data Release 2: Catalogue validation
• The Sloan Lens ACS Survey. X. Stellar, Dynamical, and Total Mass Correlations of Massive Early-type Galaxies
• Gravitationally lensed quasars and supernovae in future wide-field optical imaging surveys
• Gaia Data Release 1: Catalogue validation
• unWISE: unblurred coadds of the WISE imaging
• The Cosmic Lens All-Sky Survey:II. Gravitational lens candidate selection and follow-up
• The Sloan Lens ACS Survey. IX. Colors, Lensing and Stellar Masses of Early-type Galaxies
• Binary Quasars in the Sloan Digital Sky Survey: Evidence for Excess Clustering on Small Scales
• Quasar Microlensing at High Magnification and the Role of Dark Matter: Enhanced Fluctuations and Suppressed Saddlepoints
• A Gravitationally Lensed Quasar with Quadruple Images Separated by 14.62 Arcseconds
• WISE photometry for 400 million SDSS sources
• The Half Million Quasars (HMQ) Catalogue
• The Sloan Digital Sky Survey Quasar Lens Search. I. Candidate Selection Algorithm
• Gaia Data Release 2: processing of the photometric data
• The Sloan Digital Sky Survey Quasar Lens Search. V. Final Catalog from the Seventh Data Release
• APM 08279+5255: an ultraluminous BAL quasar at a redshift z=3.87
• Full-depth Coadds of the WISE and First-year NEOWISE-Reactivation Images
• Gaia Data Release 1, Pre-processing and source list creation
• Gravitationally Lensed Quasars in Gaia: II. Discovery of 24 Lensed Quasars
• COSMOGRAIL XVI: Time delays for the quadruply imaged quasar DES J0408-5354 with high-cadence photometric monitoring
• WFI J2026-4536 and WFI J2033-4723: Two New Quadruple Gravitational Lenses
• The Sloan Digital Sky Survey Quasar Lens Search. II. Statistical Lens Sample from the Third Data Release
• Deep Full-sky Coadds from Three Years of WISE and NEOWISE Observations
• The Sloan Digital Sky Survey Quasar Lens Search. VI. Constraints on Dark Energy and the Evolution of Massive Galaxies
• Gaia 1 and 2. A pair of new Galactic star clusters
• The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2016 follow-up campaign. I. Overview and classification of candidates selected by two techniques
• DES meets Gaia: discovery of strongly lensed quasars from a multiplet search
• Quasar Probabilities and Redshifts from WISE mid-IR through GALEX UV Photometry
• Cross-correlation of the 2XMMi catalogue with Data Release 7 of the Sloan Digital Sky Survey
• The Sloan Digital Sky Survey Quasar Lens Search. IV. Statistical Lens Sample from the Fifth Data Release
• Gravitationally Lensed Quasars in Gaia: I. Resolving Small-Separation Lenses
• A Simple Method To Find All Lensed Quasars
• First lensed quasar systems from the VST-ATLAS survey: one quad, two doubles and two pairs of lensless twins
• Quasar lenses and pairs in the VST-ATLAS and Gaia
• Five New High-Redshift Quasar Lenses from the Sloan Digital Sky Survey
• The Discovery of a Five-Image Lensed Quasar at z = 3.34 using PanSTARRS1 and Gaia
• New lensed quasars from the MUSCLES survey
• CTQ 414: A New Gravitational Lens
• Mass models and environment of the new quadruply lensed quasar SDSS J1330+1810
• The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2016 follow-up campaign. II. New quasar lenses from double component fitting
• A Search for Gravitationally Lensed Quasars and Quasar Pairs in Pan-STARRS1: Spectroscopy and Sources of Shear in the Diamond 2M1134$-$2103
• Discovery of the first quadruple gravitationally lensed quasar candidate with Pan-STARRS
• SDSS J131339.98+515128.3: A new gravitationally lensed quasar selected based on near-infrared excess
• Serendipitous discovery of quadruply-imaged quasars: two diamonds
• Discovery of three strongly lensed quasars in the Sloan Digital Sky Survey
• Unidentified quasars among stationary objects from Gaia DR2
• A fast 2D image reconstruction algorithm from 1D data for the Gaia mission
• ULAS J234311.93-005034.0: A gravitational lens system selected from UKIDSS and SDSS
• Gaia DR2 Gravitational Lens Systems I: New lensed quasar candidates around known quasars
• Discovery of the optically bright, wide separation double quasar SDSS J1442+4055
• A new gravitational lens from the MUSCLES survey: ULAS J082016.1+081216
• SDSS J1640+1932: a spectacular galaxy-quasar strong lens system
• Robust modeling of quadruply lensed quasars (and random quartets) using Witt's hyperbola
• Spectroscopic follow-up of double quasar candidates

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• Unveiling the Universe with Emerging Cosmological Probes
• When Spectral Modeling Meets Convolutional Networks: A Method for Discovering Reionization-era Lensed Quasars in Multi-band Imaging Data
• Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars
• MNELLS: The MUSE Nearby Early-Type Galaxy Lens Locator Survey
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• Constraints on the Inner Regions of Lensing Galaxies from Central Images using a Recent AGN Offset Distribution
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• Strange Quasar Candidates with Abnormal Astrometric Characteristics from Gaia EDR3 and SDSS (SQUAB-II): Optical Identifications
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