Dr Neal Turner
(JPL)
Accretion Power in Active Galactic Nuclei - Dr Neal Turner Colloquium
The nuclei of active galaxies are powered by accretion on supermassive
black holes and are among the most luminous objects known. They are a
key problem in astrophysics because they link black holes to galaxy
evolution, and because they are observed over most of the history of
the universe. A fundamental unresolved issue is how the gravitational
energy of accreting gas is converted to the photons reaching our
detectors. In objects with luminosities greater than 1% of the
Eddington limit, the inner accretion flow is thought to be an opaque,
rotating disk in which radiation pressure greatly exceeds gas
pressure. I will discuss radiation-MHD computer calculations of
patches of the disk, showing how the released energy is converted to
photons and how the radiation may escape the gas.
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