Program: GS-2011B-Q-20

Unification schemes of active galactic nuclei (AGN) account for a variety of observational differences in terms of viewing geometry. However, our recent work instead shows tantalizing hints that strong unification may not hold, and that the immediate dusty surroundings of various classes of AGN are intrinsically different. Here we propose to obtain high spatial resolution mid-infrared (MIR) images of a complete sample of Seyfert galaxies to test this hypothesis. The reprocessed AGN emission emerges predominantly in the MIR, and the MIR-emitting torus is extremely small (scales < 5 pc). Thus, the excellent angular resolution of large ground-based telescopes is essential to avoid contamination from other emission sources that arise on larger scales. Especially combining these data with high spatial resolution near-IR observations, we can effectively measure the entire dusty torus (as opposed to probing only material along the line of sight, as the absorption of type 2s does). We will derive a complete description of the dust distribution immediately around these AGN, measuring properties such as torus angular scale, dust covering fraction, and extinction. Completing observations of this sample now is crucial, as this may be the last "B" semester T-ReCS is available on Gemini South.