Probing the Broad Line Region and the Accretion Disk in the Lensed
  Quasars HE0435-1223, WFI2033-4723, and HE2149-2745 using Gravitational
  Microlensing
  We use single-epoch spectroscopy of three gravitationally lensed quasars,
HE0435-1223, WFI2033-4723, and HE2149-2745, to study their inner structure (BLR
and continuum source). We detect microlensing-induced magnification in the
wings of the broad emission lines of two of the systems (HE0435-1223 and
WFI2033-4723). In the case of WFI2033-4723, microlensing affects two "bumps" in
the spectra which are almost symmetrically arranged on the blue (coincident
with an AlIII emission line) and red wings of CIII]. These match the typical
double-peaked profile that follows from disk kinematics. The presence of
microlensing in the wings of the emission lines indicates the existence of two
different regions in the BLR: a relatively small one with kinematics possibly
related to an accretion disk, and another one that is substantially more
extended and insensitive to microlensing. There is good agreement between the
estimated size of the region affected by microlensing in the emission lines,
$r_s=10^{+15}_{-7} \sqrt{M/M_{\odot}}$ light-days (red wing of CIV in
HE0435-1223) and $r_s=11^{+28}_{-7} \sqrt{M/M_{\odot}}$ light-days (CIII] bumps
in WFI2033-4723) with the sizes inferred from the continuum emission,
$r_s=13^{+5}_{-4} \sqrt{M/M_{\odot}}$ light-days (HE0435-1223) and
$r_s=10^{+3}_{-2} \sqrt{M/M_{\odot}}$ light-days (WFI2033-4723). For
HE2149-2745 we measure an accretion disk size $r_s=8^{+11}_{-5}
\sqrt{M/M_{\odot}}$ light-days. The estimates of $p$, the exponent of the size
vs. wavelength ($r_s\propto\lambda^p$), are $1.2\pm0.6$, $0.8\pm0.2$, and
$0.4\pm0.3$ for HE0435-1223, WFI2033-4723, and HE2149-2745, respectively. In
conclusion, the continuum microlensing amplitude in the three quasars and
chromaticity in WFI2033-4723 and HE2149-2745 are below expectations for the
thin disk model. The disks are larger and their temperature gradients are
flatter than predicted by this model.
