Gaia Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Gaia Collaboration - (Author)
  • Research Group for Astronomy
  • University of California at Irvine
  • University of Lisbon
  • Université de Bordeaux
  • Observatoire de la Cote d'Azur
  • University of Liege
  • Universidade de São Paulo
  • Centre national d'études spatiales
  • Leiden University
  • Astronomical Observatory of Padua
  • ESTEC - European Space Research and Technology Centre
  • Institute for Celestial Mechanics and Computation of Ephemerides
  • IPAG - Institute of Planetology and Astrophysics of Grenoble
  • Heidelberg University 
  • University of Cambridge
  • University of Geneva
  • European Space Astronomy Centre
  • European Space Agency - ESA
  • University of Barcelona
  • Institute of Space Sciences (ICE-CSIC)
  • TUD Dresden University of Technology
  • Lund University
  • Osservatorio Astrofisico Di Arcetri, Florence
  • Polish Academy of Sciences
  • Max Planck Institute for Astronomy
  • University College London
  • National Institute for Astrophysics
  • Royal Observatory of Belgium

Abstract

Context. Strongly lensed quasars are fundamental sources for cosmology. The Gaia space mission covers the entire sky with the unprecedented resolution of 0.18âà € ³ in the optical, making it an ideal instrument to search for gravitational lenses down to the limiting magnitude of 21. Nevertheless, the previous Gaia Data Releases are known to be incomplete for small angular separations such as those expected for most lenses. Aims. We present the Data Processing and Analysis Consortium GravLens pipeline, which was built to analyse all Gaia detections around quasars and to cluster them into sources, thus producing a catalogue of secondary sources around each quasar. We analysed the resulting catalogue to produce scores that indicate source configurations that are compatible with strongly lensed quasars. Methods. GravLens uses the DBSCAN unsupervised clustering algorithm to detect sources around quasars. The resulting catalogue of multiplets is then analysed with several methods to identify potential gravitational lenses. We developed and applied an outlier scoring method, a comparison between the average BP and RP spectra of the components, and we also used an extremely randomised tree algorithm. These methods produce scores to identify the most probable configurations and to establish a list of lens candidates. Results. We analysed the environment of 3 760 032 quasars. A total of 4 760 920 sources, including the quasars, were found within 6âà € ³ of the quasar positions. This list is given in the Gaia archive. In 87% of cases, the quasar remains a single source, and in 501 385 cases neighbouring sources were detected. We propose a list of 381 lensed candidates, of which we identified 49 as the most promising ones. Beyond these candidates, the associate tables in this Focused Product Release allow the entire community to explore the unique Gaia data for strong lensing studies further.

Details

Original languageEnglish
Article numberA130
JournalAstronomy and Astrophysics
Volume685
Publication statusPublished - 1 May 2024
Peer-reviewedYes

External IDs

ORCID /0000-0002-9533-2168/work/168205409
ORCID /0000-0003-4682-7831/work/168206679
ORCID /0000-0002-9900-7864/work/168207856
ORCID /0000-0001-6967-8707/work/168207056

Keywords

Keywords

  • Catalogs, Gravitation, Gravitational lensing: strong, Methods: data analysis, Quasars: general, Surveys