New constraints on quasar broad absorption and emission line regions
  from gravitational microlensing
  Gravitational microlensing is a powerful tool allowing one to probe the
structure of quasars on sub-parsec scale. We report recent results, focusing on
the broad absorption and emission line regions. In particular microlensing
reveals the intrinsic absorption hidden in the P Cygni-type line profiles
observed in the broad absorption line quasar H1413+117, as well as the
existence of an extended continuum source. In addition, polarization
microlensing provides constraints on the scattering region. In the quasar
Q2237+030, microlensing differently distorts the H$\alpha$ and CIV broad
emission line profiles, indicating that the low- and high-ionization broad
emission lines must originate from regions with distinct kinematical
properties. We also present simulations of the effect of microlensing on line
profiles considering simple but representative models of the broad emission
line region. Comparison of observations to simulations allows us to conclude
that the H$\alpha$ emitting region in Q2237+030 is best represented by a
Keplerian disk.
