Dr Neal Turner (JPL)

Accretion Power in Active Galactic Nuclei - Dr Neal Turner Colloquium

ATNF Basement Meeting Room

Abstract

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.