UNIVERSITÄT ZU KÖLN Y ULL STOKES POLARIMETRY WITH THE EFFELSBERG 100-M RADIO TELESCOPE Inaugural – Dissertation zur Erlangung des Doktorgrades der Mathematisch – Naturalwissenschaftlichen Fakultät der Universität zu Köln vorgelegt von Elena Cenacchi aus Bologna (Italien) Köln, 2009 Berichterstatter: Prof. Dr. Andreas Eckart Prof. Dr. Anton Zensus Betreuer: Dr. Alexander Kraus Dr. Karl-Heinz Mack Tag der mündlichen Prüfung: 27. November 2009 The Effelsberg radio telescope, picture from Norbert Tacken. This research was supported by the EU Framework 6 Marie Curie Early Stage Training programme under contract number MEST-CT-2005-19669 “ESTRELA” “...it’s rather curious, you know, this sort of life! I do wonder what can have happened tome! WhenIusedtoreadfairytales,Ifanciedthatkindofthingneverhappened,andnowhereIaminthemiddleofone! Thereoughttobeabookwrittenaboutme,thatthereought!AndwhenIgrowup,I’llwriteone.”LewisCarroll,Alice’sAdventuresinWonderlandI dedi cate thisthesis to those whomakemeliveinWonder-land every day of mylife: Roberto, Marina,Isabella, Angel ica, Andreas♥“...