Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. Discovery of two bright high-redshift gravitationally lensed quasars revealed by Gaia
 
research article

Discovery of two bright high-redshift gravitationally lensed quasars revealed by Gaia

Desira, Christopher
•
Shu, Yiping
•
Auger, Matthew W.
Show more
January 1, 2022
Monthly Notices Of The Royal Astronomical Society

We present the discovery and preliminary characterisation of two high-redshift gravitationally lensed quasar systems in Gaia Data Release 2 (DR2). Candidates with multiple close-separation Gaia detections and quasar-like colours in WISE, Pan-STARRS, and DES are selected for follow-up spectroscopy with the New Technology Telescope. We confirm DLS J215028.71-465251.3 as a z = 4.130 +/- 0.006 asymmetric, doubly imaged lensed quasar system and model the lensing mass distribution as a singular isothermal sphere. The system has an Einstein radius of 1.202 +/- 0.005 arcsec and a predicted time delay of similar to 122.0 d between the quasar images, assuming a lensing galaxy redshift of z = 0.5, making this a priority system for future optical monitoring. We confirm PS J042913.17+142840.9 as a z = 3.866 +/- 0.003 four-image quasar system in a cusp configuration, lensed by two foreground galaxies. The system is well modelled using a singular isothermal ellipsoid for the primary lens and a singular isothermal sphere for the secondary lens with Einstein radii 0.704 +/- 0.006 and 0.241 +/- 0.030 arcsec, respectively. A maximum predicted time delay of 9.6 d is calculated, assuming lensing galaxy redshifts of z = 1.0. Furthermore, PS J042913.17+142840.9 exhibits a large flux ratio anomaly, up to a factor of 2.66 +/- 0.37 in i band, that varies across optical and near-infrared wavelengths. We discuss LSST and its implications for future high-redshift lens searches and outline an extension to the search using supervised machine learning techniques.

  • Details
  • Metrics
Type
research article
DOI
10.1093/mnras/stab2960
Web of Science ID

WOS:000741326000050

Author(s)
Desira, Christopher
Shu, Yiping
Auger, Matthew W.
McMahon, Richard G.
Lemon, Cameron A.  
Anguita, Timo
Neira, Favio
Date Issued

2022-01-01

Published in
Monthly Notices Of The Royal Astronomical Society
Volume

509

Issue

1

Start page

738

End page

747

Subjects

Astronomy & Astrophysics

•

Astronomy & Astrophysics

•

gravitational lensing: strong

•

methods: observational

•

quasars: general

•

active galactic nuclei

•

black-hole mass

•

cosmic evolution

•

host galaxy

•

selection

•

catalog

Editorial or Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
LASTRO  
Available on Infoscience
February 14, 2022
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/185414
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés