The cartoon on this and the three following slides was taken from
http://wwwospg.pg.infn.it/AGNcartoon.htm, a web site of the
Perugia Observatory in Italy:
http://wwwospg.pg.infn.it/.
The cartoon is adapted from the classical AGN-cartoon of Blandford R.D.:
"Active Galactic Nuclei. Saas-Fee Advanced Course 20."
1990, Berlin: Springer-Verlag
Last update: 2001-07-24 / mtt