Bachelor defense by Julie Kiel Holm

Abstract: The correlation between equivalent width (EW) of sodium absorption and host galaxy extinction is studied in core collapse supernovae. A correlation between excess sodium absorption and a preference for primarily blueshifted components, as previously found in type Ia supernovae and attributed to circumstellar material, is replicated across the different types of core collapse supernovae. No pattern of a deviation of the EW depending on the spectral type emerges from the supernovae in the studied sample. This indicates that deviations from expected values of the EW may not originate from circumstellar material.