Secondary Parameters of Type Ia Supernova Light Curves

TL;DR

This paper identifies two independent secondary parameters influencing Type Ia Supernova light curves, beyond the primary brightness decline, linked to physical variations in progenitor and accretion rates.

Contribution

It provides evidence for two secondary parameters affecting SN Ia light curves, supported by observations and models, enhancing understanding of their physical origins.

Findings

SN Ia light curves show deviations before and after maximum light.

Two independent secondary parameters influence light curve shapes.

These parameters relate to physical variations in progenitor and accretion rates.

Abstract

High-quality observations of $B$ and $V$ light curves obtained at Las Campanas Observatory for local Type Ia Supernovae (SNe Ia) show clear evidence that SNe Ia with the same brightness decline or stretch may have systematic and independent deviations at times < 5 days before and at times > 30 days after maximum light. This suggests the existence of two independent secondary parameters which control the shape of SN Ia light curves in addition to the brightness decline relation. stretch. The differences are consistent in morphology of the time dependence and size with predictions by models within the delayed detonation scenario. The secondary parameters may reflect two independent physical effects caused by variations in the progenitor and accretion rates, and link the LC variations in shape with the intrinsic, absolute brightness.