@article{GoicoecheaAlcaldeMediavillaetal.2002,
  author    = {Goicoechea, Luis Julian and Alcalde, D. and Mediavilla, E. and Munoz, J. A. and Gil-Merino, Rodrigo},
  title     = {The nature and size of the optical continuum source in QSO 2237+0305},
  year      = {2002},
  abstract  = {From the peak of a gravitational microlensing high-magnification event in the A component of QSO 2237+0305, which was accurately monitored by the Gravitational Lenses International Time Project collaboration, we derived new information on the nature and size of the optical V-band and R-band sources in the distant quasar. If the microlensing peak is caused by a microcaustic crossing, we first obtain that the standard accretion disk is a scenario more reliable/ feasible than other typical axially symmetric models. Moreover, the standard scenario fits both the V-band and R-band observations with reduced ?2 values very close to 1. Taking into account all these results, a standard accretion disk around a supermassive black hole is a good candidate for the optical continuum main source in QSO 2237+0305. Second, using the standard source model and a robust upper limit on the transverse galactic velocity, we infer that 90\% of the V- band and R-band luminosities are emitted from a region with a radial size less than 1.2×10-2 pc (=3.7×1016 cm, at a 2 ? confidence level).},
  language  = {en}
}