AbundanceTomographyofTypeIaSupernovaeMatthiasStehleAbundanceTomographyofTypeIaSupernovaeMatthiasStehleDissertationan der Fakultät für Physikder Ludwig–Maximilians–UniversitätMünchenvorgelegt vonMatthias Stehleaus SigmaringenMünchen, 4. November 2004Erstgutachter: Prof. Dr. A.W.A. PauldrachZweitgutachter: Prof. Dr. W. HillebrandtTag der mündlichen Prüfung: 22. Dezember 2004If what one finds is made of pure matter, itwill never spoil. And one can always comeback. If what you had found was only amoment of light, like the explosion of a star,you would find nothing on your return.But you experienced a light explosion, andthat was already worthwhile.Paul Coelho (1947 ),The AlchemistAbstractMany uncertainties about the physics of Type Ia Supernovae have been re vealedintherecentpast, andnumerouspiecesarepuzzledtogethertoachievea complete description of the phenomenon of thermonuclear explosions in thesky. However, very important parts are still missing. In particular, the conceptlacks a proper connection between the various evolutionary steps, namely theprogenitor scenario, explosion theory, nucleosynthesis from the burning, andtheobservations. EarlytimespectraofTypeIaSupernovaenaturallycontainin formationaboutalloftheseprocessesandareatthecentreoftheentirescenario.