Vol. 581
In section 1. Letter to the Editor

Polarimetric imaging of NGC 1068 at high angular resolution in the near infrared. Direct evidence of an extended nuclear torus

by D. Gratadour, D. Rouan, L. Grosset, A. Boccaletti, and Y. Clénet, A&A 581, L8


AGN of type 2 are assumed to be objects that are similar to AGN of type 1, but ones viewed through dust obscuration, which are supposed to come from a nearly edge-on molecular torus. High-resolution observations are needed to discover the small torus, preferably in the near-infrared to limit optical depth, and with polarimetry to distinguish it among thermal and stellar emissions. The authors have used new adaptive optics assisted polarimetric observations in the near-infrared to detect an extended nuclear torus in NGC 1068. The orientation of the polarization vectors clearly reveals a hourglass-shaped bicone and a compact elongated (20 x 60 pc) nuclear structure perpendicular to the bicone axis. The linearly polarized emission in the bicone is dominated by a centro-symmetric pattern, but the central compact region shows a clear deviation from the latter with the linear polarization aligned perpendicular to the bicone axis.