The complexity of parsec-scaled dusty tori in AGN

Abstract

Warm gas and dust surround the innermost regions of active galactic nuclei (AGN). They provide the material for accretion onto the super-massive black hole and they are held responsible for the orientation-dependent obscuration of the central engine. The AGN-heated dust distributions turn out to be very compact with sizes on scales of about a parsec in the mid-infrared. Only infrared interferometry currently provides the necessary angular resolution to directly study the physical properties of this dust. Size estimates for the dust distributions derived from interferometric observations can be used to construct a size--luminosity relation for the dust distributions. The large scatter about this relation suggests significant differences between the dust tori in the individual galaxies, even for nuclei of the same class of objects and with similar luminosities. This questions the simple picture of the same dusty doughnut in all AGN. The Circinus galaxy is the closest Seyfert 2 galaxy. Because its mid-infrared emission is well resolved interferometrically, it is a prime target for detailed studies of its nuclear dust distribution. An extensive new interferometric data set was obtained for this galaxy. It shows that the dust emission comes from a very dense, disk-like structure which is surrounded by a geometrically thick, similarly warm dust distribution as well as significant amounts of warm dust within the ionisation cone.

8 pages, 3 figures, to appear in the proceedings of the conference "The central kiloparsec in Galactic Nuclei: Astronomy at High Angular Resolution 2011", open access Journal of Physics: Conference Series (JPCS), published by IOP Publishing

References in corpus (9)

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Cited by in corpus (8)

• A diversity of dusty AGN tori: Data release for the VLTI/MIDI AGN Large Program and first results for 23 galaxies
• Revealing the large nuclear dust structures in NGC 1068 with MIDI/VLTI
• Subparsec-scale dynamics of a dusty gas disk exposed to anisotropic AGN radiation with frequency-dependent radiative transfer
• Radiation-driven outflows from and radiative support in dusty tori of active galactic nuclei
• Resolving the Hot Dust Disk of ESO323-G77
• Connection Between Mid-Infrared Emission Properties and Narrow Line Region Outflows in Type 1 Active Galactic Nuclei
• Apparent quasar disc sizes in the "bird's nest" paradigm
• Ground-Based Mid-Infrared Study of the Compton-Thick AGN in M51 at 10-100 pc Scale