Active galaxies
3.5 Mpc distant
 Milky Way (normal galaxy)
 luminosity ~ 2 x 1010 L¤
 90% galaxies normal
active galaxies (10%)
much higher luminosities 
~ 1% very high luminosity nuclei (x 1000)
radiation across e-m spectrum
 - nonstellar (not just combined radiation of many stars
Sun                             4x1026 watts        
Milky Way                 1037 watts                 2 x 1010 L¤              
Active Galaxies         1036 – 1038 watts      109 – 1012 L¤ 
Quasars                    1038 - 1042 watts      1011 – 1013 L¤