Unveiling the Diversity of Type IIn Supernovae via Systematic Light Curve Modeling

TL;DR

This study systematically models 142 Type IIn supernovae light curves, revealing their diverse properties, correlations with progenitor mass-loss rates, and implications for their origins and detection rates.

Contribution

It provides the first comprehensive analysis of SNeIIn light curves using MOSFiT, uncovering trends in CSM density, geometry, and progenitor characteristics, and estimates future detection rates.

Findings

Diverse CSM densities and geometries among SNeIIn.

Positive correlation between CSM mass and light curve timescales.

High median mass-loss rates consistent with luminous blue variable eruptions.

Abstract

Type IIn supernovae (SNeIIn) are a highly heterogeneous subclass of core-collapse supernovae, spectroscopically characterized by signatures of interaction with a dense circumstellar medium (CSM). Here we systematically model the light curves of 142 archival SNeIIn using MOSFiT (the Modular Open Source Fitter for Transients). We find that the observed and inferred properties of SNIIn are diverse, but there are some trends. The typical SN CSM is dense ($\sim$10$^{-12}$gcm$^{-3}$) with highly diverse CSM geometry, with a median CSM mass of $\sim$1M$_\odot$. The ejecta are typically massive ($\gtrsim10$M$_\odot$), suggesting massive progenitor systems. We find positive correlations between the CSM mass and the rise and fall times of SNeIIn. Furthermore there are positive correlations between the rise time and fall times and the $r$-band luminosity. We estimate the mass-loss rates of our sample (where spectroscopy is available) and find a high median mass-loss rate of $\sim$10$^{-2}$M$_\odot$yr$^{-1}$, with a range between 10$^{-4}$--1M$_\odot$yr$^{-1}$. These mass-loss rates are most similar to the mass loss from great eruptions of luminous blue variables, consistent with the direct progenitor detections in the literature. We also discuss the role that binary interactions may play, concluding that at least some of our SNeIIn may be from massive binary systems. Finally, we estimate a detection rate of 1.6$\times$10$^5$yr$^{-1}$ in the upcoming Legacy Survey of Space and Time at the Vera C. Rubin Observatory.