2018MNRAS.476..927L -
Mon. Not. R. Astron. Soc., 476, 927-932 (2018/May-1)
Serendipitous discovery of quadruply imaged quasars: two diamonds.
LUCEY J.R., SCHECHTER P.L., SMITH R.J. and ANGUITA T.
Abstract (from CDS):
Gravitationally lensed quasars are powerful and versatile astrophysical tools, but they are challengingly rare. In particular, only ∼25 well-characterized quadruple systems are known to date. To refine the target catalogue for the forthcoming Taipan Galaxy Survey, the images of a large number of sources are being visually inspected in order to identify objects that are confused by a foreground star or galaxies that have a distinct multicomponent structure. An unexpected by-product of this work has been the serendipitous discovery of about a dozen galaxies that appear to be lensing quasars, i.e. pairs or quartets of foreground stellar objects in close proximity to the target source. Here, we report two diamond-shaped systems. Follow-up spectroscopy with the IMACS instrument on the 6.5m Magellan Baade telescope confirms one of these as a z = 1.975 quasar quadruply lensed by a double galaxy at z = 0.293. Photometry from publicly available survey images supports the conclusion that the other system is a highly sheared quadruply imaged quasar. In starting with objects thought to be galaxies, our lens finding technique complements the conventional approach of first identifying sources with quasar-like colours and subsequently finding evidence of lensing.
Abstract Copyright:
© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
Journal keyword(s):
gravitational lensing: strong - quasars: individual: (2M1134-2103, 2M1310-1714)
Nomenclature:
Fig. 1, Tables 1-2: [LSS2018] 2M JHHMM+DDMM N=2, [LSS2018] 2M JHHMM+DDMM source N=2, [LSS2018] 2M JHHMM+DDMM AN N=6+9.
Simbad objects:
22
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