Review of Active Galaxies

1.  What characterizes active galaxies?



2.  What do their radiation spectra look like?



3.  How common are active galaxies?



4.  What are some examples of active galaxies?

        M87

        Centarus A

        Cygnus A



5.  What are the components of the center engine 
    of an active galaxy?



6.  What are the two types of radio galaxies?



7.  What type of radiation generates the characteristic 
    spectrum of an active galaxy?



8.  What active galaxies are spiral galaxies with 
     extremely bright nuclei?



9.  The most distant active galaxies, at distances 
    of more than 5 billion light-years, 
    are the ______________



10.  How do we know quasars are relatively small?



11.  What causes a twin quasar?



12.  What are blue arcs?