Speaker
Konrad Tristram
(MPIfR)
Description
With interferometry in the infrared it is possible to directly resolve the thermal emission from the dusty torus in Active Galactic Nuclei. We can hence for the first time directly investigate the accreting material on parsec scales and test the unified scheme of AGN.
The Circinus galaxy is ideal target for interferometric studies of its AGN-heated dust distribution, because it is the closest Seyfert 2 galaxy and the second brightest AGN in the mid-infrared. Our measurements with MIDI at the Very Large Telescope Interferometer resolve its dust distribution very well. The measurements provide evidence for a thin dust disk with a size of about 0.4 pc, which is surrounded by a larger dust component with a size of about 2 parsecs. The latter is elongated significantly in the direction of the ionisation cone, which points at significant amounts of warm dust along the polar axis of the system. In general, we find that the observations of the Circinus galaxy are in agreement with the torus paradigm, although small changes to it may be necessary to accommodate for the peculiarities of individual galaxies.
Author
Konrad Tristram
(MPIfR)