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Serendipitous discovery of quadruply imaged quasars - two diamonds

MetadataDetails
Publication Date2018-02-05
JournalMonthly Notices of the Royal Astronomical Society
AuthorsJ. R. Lucey, Paul L. Schechter, Russell J. Smith, T. Anguita
InstitutionsUniversidad Andrés Bello, Millennium Institute of Astrophysics
Citations22

Gravitationally lensed quasars are powerful and versatile astrophysical\ntools, but they are challengingly rare. In particular, only ~25\nwell-characterized quadruple systems are known to date. To refine the target\ncatalogue for the forthcoming Taipan Galaxy Survey, the images of a large\nnumber of sources are being visually inspected in order to identify objects\nthat are confused by a foreground star or galaxies that have a distinct\nmulti-component structure. An unexpected by-product of this work has been the\nserendipitous discovery of about a dozen galaxies that appear to be lensing\nquasars, i.e. pairs or quartets of foreground stellar objects in close\nproximity to the target source. Here we report two diamond-shaped systems.\nFollow-up spectroscopy with the IMACS instrument on the 6.5m Magellan Baade\ntelescope confirms one of these as a z = 1.975 quasar quadruply lensed by a\ndouble galaxy at z = 0.293. Photometry from publicly available survey images\nsupports the conclusion that the other system is a highly sheared\nquadruply-imaged quasar. In starting with objects thought to be galaxies, our\nlens finding technique complements the conventional approach of first\nidentifying sources with quasar-like colours and subsequently finding evidence\nof lensing.\n

  1. 2003 - CDS/ADC Collection of Electronic Catalogues