2003/04/22 by Naohisa Inada, R. H. Becker, Robert H. Becker +29 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Physics #Quasar #Sky #astro-ph
paper · pdf · doi:10.1086/375906
published as Astron.J. 126 (2003) 666 · 24 pages, 6 figures, accepted by AJ
arxiv created 2003/04/22 · openalex publication_date 2003/07/31 · arxiv updated 2012/08/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report the discovery of a new gravitationally lensed quasar from the Sloan Digital Sky Survey, SDSS J092455.87+021924.9 (SDSS J0924+0219). This object was selected from among known SDSS quasars by an algorithm that was designed to select another known SDSS lensed quasar (SDSS J1226-0006A,B). Five separate components, three of which are unresolved, are identified in photometric follow-up observations obtained with the Magellan Consortium's 6.5 m Walter Baade Telescope at Las Campanas Observatory. Two of the unresolved components (designated A and B) are confirmed to be quasars with z = 1.524; the velocity difference is less than 100 km s -1 according to spectra taken with the W. M. Keck Observatory's Keck II Telescope at Mauna Kea, Hawaii. A third stellar component, designated C, has the colors of a quasar with redshift similar to components A and B. The maximum separation of the point sources is 1 78. The other two sources, designated G and D, are resolved. Component G appears to be the best candidate for the lensing galaxy. Although component D is near the expected position of the fourth lensed component in a four-image lens system, its properties are not consistent with being the image of a quasar at z ∼ 1.5. Nevertheless, the identical redshifts of components A and B and the presence of component C strongly suggest that this object is a gravitational lens. Our observations support the idea that a foreground object reddens the fourth lensed component and that another unmodeled effect (such as micro- or millilensing) demagnifies it, but we cannot rule out the possibility that SDSS J0924+0219 is an example of the relatively rare class of "three-component" lens systems.