出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present the main results of the first long-term spectrophotometric monitoring of the “Einstein
cross” Q2237+0305 and of the single-epoch spectra of the lensed quasar J1131-1231.
From October 2004 to December 2006, we find that two prominent microlensing events affect
images A & B in Q2237+0305 while images C & D remain grossly unaffected by microlensing
on a time scale of a few months. Microlensing in A & B goes with chromatic variations of the
quasar continuum. We observe stronger micro-amplification in the blue than in the red part of the
spectrum, as expected for continuum emission arising from a standard accretion disk. Microlensing
induced variations of the CIII] emission are observed both in the integrated line intensity and
profile. Finally, we also find that images C & D are about 0.1-0.3 mag redder than images A & B.
The spectra of images A-B-C in J1131-1231 reveal that, in April 2003, microlensing was at work
in images A and C.We find that microlensing de-amplifies the continuum emission and the Broad
Line Region (BLR) in these images. Contrary to the case of Q2237+0305, we do not find evidence
for chromatic microlensing of the continuum emission. On the other hand, we observe
that the Balmer and Mg II broad line profiles are deformed by microlensing. These deformations
imply an anti-correlation between the width of the emission line and the size of the corresponding
emitting region. Finally, the differential microlensing of the Fe II emission suggests that the bulk
of Fe II is emitted in the outer parts of the BLR while another fraction of Fe II is produced in a
compact region.
