What are the common properties shared by most active galaxies and ...

[joe]

What are the common properties shared by most active galaxies and quasars? How do these properties lead to an understanding of the central engine?
 
  What will be an ideal response?

Question 2

The observed spectral lines of a star are all shifted towards the red end of the spectrum. Which statement is true?
 
  A) The star is not rotating.
  B) This is an example of the photoelectric effect.
  C) This is an example of the Doppler effect.
  D) The star has a radial velocity towards us.
  E) The second law of Kirchhoff explains this.

[catron30]

Answer to Question 1

All active galaxies and quasars emit massive quantities of radio- and infrared-wavelength energy in a non-blackbody spectrum from a very small (solar-system-sized) source. This can be understood if they are powered by the energy produced when matter falls into a supermassive black hole.

Answer to Question 2

C