The Evolution of the Type Ia Supernova Luminosity Function

Understand

Type Ia supernovae (SNe Ia) exhibit a wide diversity of peak luminosities and light curve shapes: the faintest SNe Ia are 10 times less luminous and evolve more rapidly than the brightest SNe Ia.

• Their differing characteristics also extend to their stellar age distributions, with fainter SNe Ia preferentially occurring in old stellar populations and vice versa.
• In this Letter, we quantify this SN Ia luminosity - stellar age connection using data from the Lick Observatory Supernova Search (LOSS).
• Our binary population synthesis calculations agree qualitatively with the observed trend in the >1 Gyr-old populations probed by LOSS if the majority of SNe Ia arise from prompt detonations of sub-Chandrasekhar mass white dwarfs (WDs) in double WD systems.