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arXiv · 1809.07337

SDSS J0909$+$4449: A Large-separation Strongly Lensed Quasar at $z \sim 2.8$ with Three Images

Yiping Shu·Rui Marques-Chaves·N. Wyn Evans·Ismael Pérez-Fournon
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Abstract

We report the discovery of SDSS J0909$+$4449, an exceptional system consisting of a quasar at $z=2.788$ strongly lensed by a group of galaxies at $z \sim 0.9$ into three images separated by up to 14\arcsec\, based on archival data collected by the Sloan Digital Sky Survey, extended Baryon Oscillation Spectroscopic Survey, Beijing--Arizona Sky Survey, the Mayall z-band Legacy Survey, and the Gemini Telescope. We discuss two hypotheses on the nature of SDSS J0909$+$4449, i.e. a rare triply-imaged quasar in the naked cusp configuration and a typical quadruply-imaged quasar with the fourth image undetected in the current data. We find that simple lens models can provide excellent fits to the observed image positions and the non-detection under either hypothesis. Deeper imaging data, spectroscopic observations, and follow-up light curve measurements will be helpful in determining which hypothesis is correct and provide better constraints on the lens mass distribution. Nevertheless, given its unusually large image separations, SDSS J0909$+$4449 will be a unique probe for the mass structure and the underlying cooling and stellar feedback processes on group or cluster scales.

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Yiping Shu, Rui Marques-Chaves, N. Wyn Evans, Ismael Pérez-Fournon. 2018-09-19. SDSS J0909$+$4449: A Large-separation Strongly Lensed Quasar at $z \sim 2.8$ with Three Images. https://doi.org/10.1093/mnrasl/sly174

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