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We present the discovery of four gravitationally lensed quasars selected from the spectroscopic quasar catalog of the Sloan Digital Sky Survey (SDSS). We describe imaging and spectroscopic follow-up observations that support the lensing interpretation of the following four quasars: SDSS J0832+0404 (image separation θ = 1 98, source redshift z s = 1.115, lens redshift z l = 0.659); SDSS J1216+3529 (θ = 1 49, z s = 2.012); SDSS J1322+1052 (θ = 2 00, z s = 1.716); and SDSS J1524+4409 (θ = 1 67, z s = 1.210, z l = 0.320). Each system has two lensed images. We find that the fainter image component of SDSS J0832+0404 is significantly redder than the brighter component, perhaps because of differential reddening by the lensing galaxy. The lens potential of SDSS J1216+3529 might be complicated by the presence of a secondary galaxy near the main lensing galaxy.
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Oguri et al. (2008) studied this question.
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