NRAO/Socorro Colloquium Series
David Whysong
National Radio Astronomy Observatory
Obscured Quasars in 3CR FR-II Radio Galaxies...Performing AGN
Statistics of a Higher Moral Character
The 'unified model' of active galactic nuclei has been very successful
in explaining the observed properties of different kinds of active
galaxies in terms of the relative orientation of a dusty torus
surrounding a powerful source of optical/UV radiation, thought to
result from accretion onto a central black hole. The torus re-radiates
the absorbed optical/UV in the mid-infrared region. So for obscured
AGN, the torus mid-IR luminosity can be used as a calorimeter for the
hidden optical/UV emission. We obtained Spitzer mid-infrared spectra
for a complete sample of FR-II radio sources, selected from the 3CR
catalog. Most of the radio galaxies which are smaller in projected
linear size have less mid-infrared emission than otherwise similar but
larger radio galaxies and quasars, and therefore do not contain
powerful hidden quasars. The radio power in the small galaxies may be
extracted mostly from black hole rotation or from radiatively
inefficient accretion.
27 October 2006
11:00 a.m.
Array Operations Center Auditorium
All NRAO employees are invited to attend via
video, available in Charlottesville Room 230, Green Bank Room 137 and
Tucson N525.
Local Host: