2003MNRAS.340..733R

We present subarcsec resolution imaging polarimetry of the Seyfert 1 galaxy NGC 4151 in the J (1.23 µm) and H (1.64 µm) bands. The polarized flux images show elongated emission in both near-infrared bands, mainly to the north-east along a position angle of 30°. Detailed modelling indicates that the observed polarization can be reproduced by scattering in a very broad bi-conical structure, and in the region of the disc of the host galaxy illuminated by the AGN. The forward scattering and illumination cone has a half-opening angle of 60° and is at an inclination of 40° to the line of sight. To produce the best fit to the observations, an optically thick torus is required to attenuate the view to the bulk of the counter-scattering cone in the north-eastern direction. This torus has an outer radius of ~15 pc, consistent with the constraints from radio observations.