Optical studies of a bright Type Iax supernova SN 2020rea

TL;DR

This study presents detailed optical photometric and spectroscopic analysis of the bright Type Iax supernova SN 2020rea, revealing properties consistent with a pure deflagration model of a Chandrasekhar mass white dwarf.

Contribution

First detailed optical analysis of SN 2020rea, demonstrating its consistency with pure deflagration models and expanding understanding of Type Iax supernovae.

Findings

SN 2020rea has a decline rate similar to SNe 2012Z and 2005hk.

Spectral features resemble SN 2012Z, with iron group element dominance.

Physical properties support a pure deflagration explosion of a Chandrasekhar mass white dwarf.

Abstract

We present optical photometric and spectroscopic analysis of a Type Iax supernova (SN) 2020rea situated at the brighter luminosity end of Type Iax supernovae (SNe). The light curve decline rate of SN~2020rea is $\Delta$m$_{15}$(g) = 1.31$\pm$0.08 mag which is similar to SNe 2012Z and 2005hk. Modelling the pseudo bolometric light curve with a radiation diffusion model yields a mass of $^{56}$Ni of 0.13$\pm$0.01 M$_{\odot}$ and an ejecta mass of 0.77$^{+0.11}_{-0.21}$ M$_{\odot}$. Spectral features of SN~2020rea during the photospheric phase show good resemblance with SN 2012Z. TARDIS modelling of the early spectra of SN~2020rea reveals a dominance of Iron Group Elements (IGEs). The photospheric velocity of the Si {\sc II} line around maximum for SN~2020rea is $\sim$ 6500 km s$^{-1}$ which is less than the measured velocity of the Fe {\sc II} line and indicates significant mixing. The observed physical properties of SN~2020rea match with the predictions of pure deflagration model of a Chandrasekhar mass C-O white dwarf. The metallicity of the host galaxy around the SN region is 12+log(O/H) = 8.56$\pm$0.18 dex which is similar to that of SN 2012Z.