Pulsational Pair-Instability Model for Superluminous Supernova PTF12dam: Interaction and Radioactive Decay

TL;DR

This paper models the superluminous supernova PTF12dam as a pulsational pair-instability event, combining radioactive decay and shock interaction to accurately reproduce observed light curves and spectra.

Contribution

It introduces a novel pulsational pair-instability model for PTF12dam, integrating radioactive decay and circumstellar interaction, supported by radiation hydrodynamics simulations.

Findings

Light curves are well fitted with 40 solar mass ejecta and 20-40 solar mass circumstellar medium.

Ejected $^{56}$Ni mass is about 6 solar masses, from explosive nucleosynthesis.

Model reproduces observed photometric characteristics, including light curves, temperatures, and velocities.

Abstract

Being a superluminous supernova (SLSN), PTF12dam can be explained by a $^{56}$Ni-powered model, a magnetar-powered model or an interaction model. We propose that PTF12dam is a pulsational pair instability supernova, where the outer envelope of a progenitor is ejected during the pulsations. Thus, it is powered by double energy source: radioactive decay of $^{56}$Ni and a radiative shock in a dense circumstellar medium. To describe multicolor light curves and spectra we use radiation hydrodynamics calculations of STELLA code. We found that light curves are well described in the model with 40M$_{\odot}$ ejecta and 20-40M$_{\odot}$ circumstellar medium. The ejected $^{56}$Ni mass is about 6M$_{\odot}$ which results from explosive nucleosynthesis with large explosion energy (2-3)$\cdot$10$^{52}$ ergs. In comparison with alternative scenarios of pair-instability supernova and magnetar-powered supernova, in interaction model all the observed main photometric characteristics are well reproduced: multicolor light curves, color temperatures, and photospheric velocities.