Abstract

We use spectra of the double-lensed quasars HE0047-1756 and SDSS1155+6346 to study their unresolved structure through the impact of microlensing. There is no significant evidence of microlensing in the emission line profiles except for the Ly alpha line of SDSS1155+6346, which shows strong differences in the shapes for images A and B. However, the continuum of the B image spectrum in SDSS1155+6346 is strongly contaminated by the lens galaxy, and these differences should be considered with caution. Using the flux ratios of the emission lines for image pairs as a baseline to remove macro-magnification and extinction, we have detected strong chromatic microlensing in the continuum measured by CASTLES (www.cfa.harvard.edu/castles/)in both lens systems, with amplitudes 0.09(lambda 16000) less than or similar to vertical bar Delta m vertical bar less than or similar to 0.8(lambda 5439) for HE0047-1756, and 0.2(.16000) less than or similar to vertical bar Delta m vertical bar less than or similar to 0.8(lambda 5439) for SDSS1155+6346. Using magnification maps to simulate microlensing and modeling the accretion disk as a Gaussian source (I alpha exp(-R-2/2r(s)(2))) of size r(s) alpha lambda(p),we find r(s) = 2.5(-1.4)(+3.0) root M/0.3M(circle dot) lt-day and p = 2.3 +/- 0.8 at the rest frame for lambda = 2045 for HE0047-1756 (log prior) and r(s) = 5.5(-3.3)(+8.2) root M/0.3M(circle dot) lt-day and p = 1.5 +/- 0.6 at the rest frame of lambda = 1398 for SDSS1155+6346 (log prior). Contrary to other studied lens systems, the chromaticity detected in HE0047-1756 and SDSS1155+6346 is large enough to fulfill the thin disk prediction. The inferred sizes, however, are very large compared to the predictions of this model, especially in the case of SDSS1155+6346.