What is the unified model of active galactic nuclei? How does it ...

[luminitza]

What is the unified model of active galactic nuclei? How does it explain differences in the continuous spectrum and emission lines of an active galactic nucleus?
 
  What will be an ideal response?

Question 2

Granulation is caused by convection currents just below the photosphere.
 
  a. True
  b. False
  Indicate whether the statement is true or false

[tdewitt]

Answer to Question 1

A supermassive black hole is the centerpiece of the unified model. According to the unified model, what you see when you view the core of an active galaxy depends on how the black hole's accretion disk is tipped with respect to the observer's line of sight.

If the accretion disk is viewed edge-on, the central area cannot be seen because the thick, dusty outer torus of the accretion disk blocks the view of the center. The visible gas is further from the central black hole. It is cooler, orbits more slowly, and produces less broad spectral lines. The hottest gas cannot be seen because it is obscured by the cool edge of the accretion disk.

If the accretion disk is tipped away from edge-on, the observer can see more of the hot gas in the central cavity of the accretion disk. This region emits broad emission lines because the hot gas is orbiting at very high velocities. The view of hotter gas allows more X-ray emission to be seen.

Answer to Question 2

True