Using Nearby Supernova factory data to shed light on SNe Ia Physics
Understanding Type Ia supernovae from first principles is a difficult
task. While there is general agreement about the physics that create
the Phillips relation, the underlying progenitor, explosion mechanism,
and additional diversity are not well understood.
Using 184 spectro-photometric time series gathered by the Nearby Supernova factory we find a flux plateau of Type Ia supernovae (SNe Ia) in the spectral region between 6125 and 6200 angstroms about 22 days after maximum light. This plateau can be related to the light curve shape parameters (as determined by SALT2) and correlated to Hubble residuals. Using some synthetic spectral time series produced with PHOENIX we find the plateau is likely related to the FeII/FeIII ionization front. This plateau could allow us to relate a physical property to some of the additional intrinsic variability of SNe Ia.
Future work involves more model comparisons as well as a deeper understanding of the light curve shape correlations.