PISN 2018ibb: radioactive emission of [O III] lines

TL;DR

This paper proposes a model explaining the origin of strong [O III] emission lines in supernova 2018ibb, suggesting they result from radioactive decay heating oxygen matter, and discusses the variability of line luminosity in PISN supernovae.

Contribution

A simple model is introduced that links [O III] emission lines to radioactive decay heating in PISN supernovae, explaining their variability and uncertain origin.

Findings

[O III] lines can originate from radioactive decay heating of oxygen matter.

The model accounts for the broad range of observed [O III] line luminosities.

The origin of [O III] emission in PISN is linked to $^{56}$Co decay processes.

Abstract

Supernova 2018ibb of the PISN category related to the dynamical instability of oxygen core in a supermassive star induced by pair-creation shows at the nebular stage strong [\oiii] emission lines of an uncertain origin. I propose a simple model that demonstrates a possibility of [O III] lines emission from the supernova oxygen matter ionized and heated by the $^{56}$Co radioactive decay. The reason is pinpointed by which the [O III] line luminosity among supernovae of PISN category can vary in a broad range.