Polarization microlensing in the quadruply imaged broad absorption line quasar H1413+117

Abstract

We have obtained spectropolarimetric observations of the four images of the gravitationally lensed broad absorption line quasar H1413+117. The polarization of the microlensed image D is significantly different both in the continuum and in the broad lines from the polarization of image A which is essentially unaffected by microlensing. The observations suggest that the continuum is scattered off two regions spatially separated and producing roughly perpendicular polarizations. These results are compatible with a model in which the microlensed polarized continuum comes from a compact region located in the equatorial plane close to the accretion disk and the non-microlensed continuum from an extended region located along the polar axis.

Accepted for publication in Astronomy and Astrophysics; minor changes (language editing)