Modeling the reverberation of optical polarization in AGN
  According to the standard paradigm, the strong and compact luminosity of
active galactic nuclei (AGN) is due to multi-temperature black body emission
originating from an accretion disk formed around a supermassive black hole.
This central engine is thought to be surrounded by a dusty region along the
equatorial plane and by ionized winds along the poles. The innermost regions
cannot yet be resolved neither in the optical nor in the infrared and it is
fair to say that we still lack a satisfactory understanding of the physical
processes, geometry and composition of the central (sub-parsec) components of
AGN. Like spectral or polarimetric observations, the reverberation data needs
to be modeled in order to infer constraints on the AGN geometry (such as the
inner radius or the half-opening angle of the dusty torus). In this research
note, we present preliminary modeling results using a time-dependent Monte
Carlo method to solve the radiative transfer in a simplified AGN set up. We
investigate different model configurations using both polarization and time
lags and find a high dependency on the geometry to the time-lag response. For
all models there is a clear distinction between edge-on or face-on viewing
angles for fluxes and time lags, the later showing a higher
wavelength-dependence than the former. Time lags, polarization and fluxes point
toward a clear dichotomy between the different inclinations of AGN, a method
that could help us to determine the true orientation of the nucleus in Seyfert
galaxies.
