Examinando por Autor "Oldham L."

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    Discovery of three strongly lensed quasars in the Sloan Digital Sky Survey
    (Oxford University Press, 2018-06) Williams P.R.; Agnello A.; Treu T.; Apostolovski Y.; Chen G.C.; Fassnacht C.D.; Hsueh J.W.; Lemaux B.C.; Motta V.; Oldham L.; Rojas K.; Rusu C.E.; Shajib A.J.; Wang X.; Abramson L.E.
    We present the discovery of three quasar lenses in the Sloan Digital Sky Survey, selected using two novel photometry-based selection techniques. The J0941+0518 system, with two point sources separated by 5.46 arcsec on either side of a galaxy, has source and lens redshifts 1.54 and 0.343. Images of J2257+2349 show two point sources separated by 1.67 arcsec on either side of an E/S0 galaxy. The extracted spectra show two images of the same quasar at zs = 2.10. SDSS J1640+1045 has two quasar spectra at zs = 1.70 and fits to the SDSS and Pan-STARRS images confirm the presence of a galaxy between the two point sources. We observed 56 photometrically selected lens candidates in this follow-up campaign, confirming three new lenses, re-discovering one known lens, and ruling out 36 candidates, with 16 still inconclusive. This initial campaign demonstrates the power of purely photometric selection techniques in finding lensed quasars. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.