Published May 1, 2017 | Version v1
Journal article

First Lensed Quasar Systems from the VST-ATLAS Survey: One Quad, Two Doubles, and Two Pairs of Lensless Twins

  • 1. MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States)
  • 2. Staples High School, Westport, CT 06880 (United States)
  • 3. Durham University, Durham DH1 3LE (United Kingdom)

Description

We have analyzed images from the VST-ATLAS survey to identify candidate gravitationally lensed quasar systems in a sample of WISE sources with W 1 W 2 > 0.7. Results from follow-up spectroscopy with the Baade 6.5 m telescope are presented for eight systems. One of them is a quadruply lensed quasar, and two are doubly lensed systems. Two are projected superpositions of two quasars at different redshifts. In one system, two quasars, although at the same redshift, have very different emission line profiles and constitute a physical binary. In two systems, the component spectra are consistent with the lensing hypothesis, after allowing for microlensing. However, as no lensing galaxy is detected in these two systems, we classify them as lensless twins. More extensive observations are needed to establish whether they are in fact lensed quasars or physical binaries.

Availability note (English)

Available from http://dx.doi.org/10.3847/1538-3881/aa6899

Additional details

Identifiers

Publishing Information

Journal Title
Astronomical Journal (New York, N.Y. Online)
Journal Volume
153
Journal Issue
5
Journal Page Range
[12 p.]
ISSN
1538-3881

INIS

Country of Publication
United States
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
51024864
Subject category
S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
Descriptors DEI
EMISSION; GALAXIES; GRAVITATIONAL LENSES; HYPOTHESIS; IMAGES; QUASARS; RED SHIFT; SPECTRA; SPECTROSCOPY; TELESCOPES
Descriptors DEC
COSMIC RADIO SOURCES; LENSES