A comparative study of Type II-P and II-L supernova rise times as exemplified by the case of LSQ13cuw

TL;DR

This study compares the rise times and peak brightness of Type II-P and II-L supernovae, revealing correlations with progenitor properties and providing insights into their physical differences and explosion mechanisms.

Contribution

It offers the first detailed comparative analysis of Type II-P and II-L supernova rise times using well-constrained explosion epochs and models physical parameters influencing these characteristics.

Findings

SNe II-L tend to have brighter peaks and longer rise times than SNe II-P.

A positive correlation exists between rise time duration and peak brightness.

Progenitor radius and explosion energy significantly influence the rise time and brightness.

Abstract

We report on our findings based on the analysis of observations of the Type II-L supernova LSQ13cuw within the framework of currently accepted physical predictions of core-collapse supernova explosions. LSQ13cuw was discovered within a day of explosion, hitherto unprecedented for Type II-L supernovae. This motivated a comparative study of Type II-P and II-L supernovae with relatively well-constrained explosion epochs and rise times to maximum (optical) light. From our sample of twenty such events, we find evidence of a positive correlation between the duration of the rise and the peak brightness. On average, SNe II-L tend to have brighter peak magnitudes and longer rise times than SNe II-P. However, this difference is clearest only at the extreme ends of the rise time versus peak brightness relation. Using two different analytical models, we performed a parameter study to investigate the physical parameters that control the rise time behaviour. In general, the models qualitatively reproduce aspects of the observed trends. We find that the brightness of the optical peak increases for larger progenitor radii and explosion energies, and decreases for larger masses. The dependence of the rise time on mass and explosion energy is smaller than the dependence on the progenitor radius. We find no evidence that the progenitors of SNe II-L have significantly smaller radii than those of SNe II-P.