Environmental dependence of Type IIn supernova properties

TL;DR

This study explores how the properties of Type IIn supernovae relate to their local environments, revealing correlations with metallicity and stellar population age, and suggesting insights into their progenitors and mass-loss mechanisms.

Contribution

It provides new observational evidence linking supernova luminosity and environment characteristics, advancing understanding of Type IIn supernova progenitors and circumstellar matter formation.

Findings

Higher luminosity supernovae occur in lower metallicity environments.

Circumstellar matter density shows no significant metallicity correlation.

Younger stellar populations are associated with more luminous supernovae.

Abstract

Type IIn supernovae occur when stellar explosions are surrounded by dense hydrogen-rich circumstellar matter. The dense circumstellar matter is likely formed by extreme mass loss from their progenitors shortly before they explode. The nature of Type IIn supernova progenitors and the mass-loss mechanism forming the dense circumstellar matter are still unknown. In this work, we investigate if there are any correlations between Type IIn supernova properties and their local environments. We use Type IIn supernovae with well-observed light-curves and host-galaxy integral field spectroscopic data so that we can estimate both supernova and environmental properties. We find that Type IIn supernovae with a higher peak luminosity tend to occur in environments with lower metallicity and/or younger stellar populations. The circumstellar matter density around Type IIn supernovae is not significantly correlated with metallicity, so the mass-loss mechanism forming the dense circumstellar matter around Type IIn supernovae might be insensitive to metallicity.