Reconstruction of the quasar brightness profile from observations of   high magnification events
  The analysis of the high magnification events in the A and C components of the quadruple gravitational lens QSO2237+0305 observed by OGLE and GLITP collaborations in V band was carried out. The significant light amplifications of the components are interpreted as the effect of microlensing with a fold caustic. For the reconstruction of the one-dimensional source profile the technique based on Tikhonov regularization method was used. The estimates of the effective radius of the quasar's emitting region (the radius within which half of the light is emitted) based on reconstructed profile of the source from microlensing of the A and C components are in the range of 31 and 21 days and correspond to the linear sizes 0.62e+15 cm and 0.42e+15 cm. For the A component the positive crossing of the caustic and for the C component the negative crossing of the caustic was confirmed. 
Ekaterina Koptelova, Elena Shimanovskaya