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Unformatted text preview: narrower than the broad lines. Radio continuum emission. This is always due to a jet. It shows a spectrum characteristic of synchrotron radiation. X-ray continuum emission. This can arise both from a jet and from the hot corona of the accretion disc via scattering processes: in both cases it shows a power-law spectrum. In some radio-quiet AGN there is a `soft excess' in the X-ray emission in addition to the power-law component. The origin of the soft excess is not clear at present. X-ray line emission. This is a result of illumination of cold heavy elements by the X-ray continuum. Fluorescence gives rise to various emission lines, the best-known of which is the iron feature around 6.4 keV . This line may be narrow or broad: relativistically broadened iron lines can be used to study the dynamics of the accretion disc very close to the nucleus and therefore the nature of the central black hole....
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This note was uploaded on 12/15/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.
- Fall '10