WFI J2026-4536 and WFI J2033-4723: Two New Quadruple Gravitational Lenses

We report the discovery of two new gravitationally lensed quasars, WFIJ2026-4536 and WFI J2033-4723, at respective source redshifts of z=2.23 andz=1.66. Both systems are quadruply imaged and have similar PG1115-like imageconfigurations. WFI J2026-4536 has a maximum image separation of 1.4", a totalbrightness of g = 16.5, and a relatively simple lensing environment, while WFIJ2033-4723 has a maximum image separation of 2.5", an estimated totalbrightness of g = 17.9, and a more complicated environment of at least sixgalaxies within 20". The primary lensing galaxies are detected for both systemsafter PSF subtraction. Several of the broadband flux ratios for the two lensesshow a strong (0.1-0.4 mags) trend with wavelength, suggesting eithermicrolensing or differential extinction through the lensing galaxy. For WFIJ2026-4536, the total quasar flux has dimmed by 0.1 mag in the blue but onlyhalf as much in the red over three months, suggestive of microlensing-inducedvariations. For WFI J2033-4723, resolved spectra of some of the quasarcomponents reveal emission line flux ratios that agree better with themacromodel predictions than either the broadband or continuum ratios, alsoindicative of microlensing. The predicted differential time delays for WFIJ2026-4536 are short, ranging from 1-2 weeks for the long delay, but are longerfor WFI J2033-4723, ranging from 1-2 months. Both systems hold promise forfuture monitoring campaigns aimed at microlensing or time delay studies.Comment: 34 pages, including 9 postscript figures. Submitted to A