OGLE14-073 - a promising pair-instability supernova candidate

TL;DR

This paper investigates OGLE14-073 as a potential pair-instability supernova by modeling its light curve and spectra, suggesting it is a promising candidate for this rare explosion mechanism.

Contribution

The study presents detailed explosion models and spectral simulations supporting OGLE14-073 as a pair-instability supernova candidate, incorporating hydrogen mixing and nickel distribution.

Findings

Models fit observed light curves with additional 56Ni and hydrogen mixing.

Synthetic spectra match observed spectral features.

Supports OGLE14-073 as a promising pair-instability supernova candidate.

Abstract

The recently discovered bright type II supernova OGLE14-073 evolved very slowly. The light curve rose to maximum for 90 days from discovery and then declined at a rate compatible with the radioactive decay of 56Co. In this study, we show that a pair-instability supernova is a plausible mechanism for this event. We calculate explosion models and light curves with the radiation hydrodynamics code STELLA starting from two M(ZAMS) = 150 solar masses, Z=0.001 progenitors. We obtain satisfactory fits to OGLE14-073 broadband light curves by including additional 56Ni in the centre of the models and mixing hydrogen down into the inner layers of the ejecta to a radial mass coordinate of 10 solar masses. The extra 56Ni required points to a slightly more massive progenitor star. The mixing of hydrogen could be due to large scale mixing during the explosion. We also present synthetic spectra for our models simulated with the Monte Carlo radiative transfer code ARTIS. The synthetic spectra reproduce the main features of the observed spectra of OGLE14-073. We conclude that OGLE14-073 is one of the most promising candidates for a pair-instability explosion.