Bibcode
Levenson, Nancy A.; Ramos Almeida, Cristina; Rodriguez Espinosa, Jose Miguel; Packham, Chris; Mason, Rachel; Radomski, James; Alonso-Herrero, Almudena; Elitzur, Moshe; Diaz Santos, Tanio
Referencia bibliográfica
NOAO Proposal ID #2009B-0183
Fecha de publicación:
8
2009
Número de citas
0
Número de citas referidas
0
Descripción
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 Seyfert 1
galaxies to test this hypothesis. These new observations will supplement
our existing sample of Seyfert galaxies, in which the limited number of
type 1s prevents us from drawing statistically robust conclusions
against the larger number of type 2s. The MIR-emitting torus is
extremely small (scales < 5 pc), so the excellent angular resolution
of large ground-based telescopes is essential to avoid contamination
from other emission sources that arise on larger scales. Combining these
data with existing 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.