The Flavours of SN II Light Curves

TL;DR

This paper classifies Type II supernova light curves into three main categories, suggesting distinct progenitor systems and highlighting differences in luminosity and plateau duration, with implications for supernova origins.

Contribution

It provides a new classification scheme for Type II supernova light curves and links these classes to different progenitor systems, supporting a binary origin hypothesis.

Findings

Most light curves fall into three classes: plateau, slowly declining, rapidly declining.

Rapidly declining SNe are exclusively Type IIb, similar to SNe Ib.

Plateau luminosity varies widely, but plateau duration is consistently around 100 days.

Abstract

We present R-Band light curves of Type II supernovae (SNe) from the Caltech Core Collapse Program (CCCP). With the exception of interacting (Type IIn) SNe and rare events with long rise times, we find that most light curve shapes belong to one of three distinct classes: plateau, slowly declining and rapidly declining events. The latter class is composed solely of Type IIb SNe which present similar light curve shapes to those of SNe Ib, suggesting, perhaps, similar progenitor channels. We do not find any intermediate light curves, implying that these subclasses are unlikely to reflect variance of continuous parameters, but rather might result from physically distinct progenitor systems, strengthening the suggestion of a binary origin for at least some stripped SNe. We find a large plateau luminosity range for SNe IIP, while the plateau lengths seem rather uniform at approximately 100 days. We present also host galaxy trends from the Palomar Transient Factory (PTF) core collapse SN sample, which augment some of the photometric results.