Supernovae in Early-Type Galaxies: Directly Connecting Age and Metallicity with Type Ia Luminosity

Understand

We have obtained optical spectra of 29 early-type (E/S0) galaxies that hosted type Ia supernovae (SNe Ia).

• We have measured absorption-line strengths and compared them to a grid of models to extract the relations between the supernova properties and the luminosity-weighted age/composition of the host galaxies.
• The same analysis was applied to a large number of early-type field galaxies selected from the SDSS spectroscopic survey.
• We find no difference in the age and abundance distributions between the field galaxies and the SN Ia host galaxies.