NRAO/Socorro Colloquium Series
Joan Wrobel
NRAO
Massive Black Holes in
Quiescence
Low-luminosity
active galactic nuclei (LLAGNs) are often found in
nearby galaxies. Energized by black holes with masses of 1e6 to 1e9 Solar masses, these LLAGNs are characterized
by Eddington ratios in the range 1e-3 to 1e-6.
Observations of these sub-Eddington accretors imply that the massive black hole is surrounded
by an inner radiatively-inefficient accretion flow, a
truncated outer thin disk, and a jet or outflow. Guided by this framework, a
few nearby galaxies have been searched for the accretion signatures of massive
black holes in quiescence, that is, those with Eddington
ratios below 1e-6. Search results will be summarized and their implications
will be explored. The prospects for improved searches will also be
examined.
November 14, 2008
11:00 am
Array Operations
Center
Auditorium
All NRAO employees are
invited to attend via video, available in Charlottesville Room ER209, Green
Bank Room BSMT and Tucson
N525.
Local Host: Mark Claussen