The Local Environments of Core-Collapse SNe within Host Galaxies

TL;DR

This study examines the environments of core-collapse supernovae within host galaxies, revealing correlations between supernova types, star formation, and metallicity, to infer progenitor characteristics.

Contribution

It introduces a dual approach using pixel statistics and HII region spectroscopy to analyze supernova environments, providing new insights into progenitor properties.

Findings

Supernova types show increasing association with star formation from Ia to Ic.

Type IIn supernovae have lower star formation association than IIPs, suggesting lower mass progenitors.

Type Ibc supernovae occur in slightly higher metallicity environments than Type II, but the difference is not significant.

Abstract

We present constraints on core-collapse supernova progenitors through observations of their environments within host galaxies. This is achieved through 2 routes. Firstly, we investigate the spatial correlation of supernovae with host galaxy star formation using pixel statistics. We find that the main supernova types form a sequence of increasing association to star formation. The most logical interpretation is that this implies an increasing progenitor mass sequence going from the supernova type Ia arising from the lowest mass, through the type II, type Ib, and the supernova type Ic arising from the highest mass progenitors. We find the surprising result that the supernova type IIn show a lower association to star formation than type IIPs, implying lower mass progenitors. Secondly, we use host HII region spectroscopy to investigate differences in environment metallicity between different core-collapse types. We find that supernovae of types Ibc arise in slightly higher metallicity environments than type II events. However, this difference is not significant, implying that progenitor metallicity does not play a dominant role in deciding supernova type.