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arXiv · 2305.12713

Observational properties of a bright type Iax SN 2018cni and a faint type Iax SN 2020kyg

Mridweeka Singh·Devendra. K. Sahu·Raya Dastidar·Barnabas Barna·Kuntal Misra·Anjasha Gangopadhyay·D. Andrew Howell·Saurabh W. Jha·Hyobin Im·Kirsty Taggart·Jennifer Andrews·Daichi Hiramatsu·Rishabh Singh Teja·Craig Pellegrino·Ryan J. Foley·Arti Joshi·G. C. Anupama·K. Azalee Bostroem·Jamison Burke·Yssavo Camacho-Neves·Anirban Dutta·Lindsey A. Kwok·Curtis McCully·Yen-Chen Pan·Matt Siebert·Shubham Srivastav·Tamas Szalai·Jonathan J. Swift·Grace Yang·Henry Zhou·Nico DiLullo·Jackson Scheer
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Abstract

We present the optical photometric and spectroscopic analysis of two type Iax SNe 2018cni and 2020kyg. SN 2018cni is a bright type Iax SN (M$_{V,peak}$ = $-$17.81$\pm$0.21 mag) whereas SN 2020kyg (M$_{V,peak}$ = $-$14.52$\pm$0.21 mag) is a faint one. We derive $^{56}$Ni mass of 0.07 and 0.002 M${_\odot}$, ejecta mass of 0.48 and 0.14 M${_\odot}$ for SNe 2018cni and 2020kyg, respectively. A combined study of the bright and faint type Iax SNe in $R/r$- band reveals that the brighter objects tend to have a longer rise time. However, the correlation between the peak luminosity and decline rate shows that bright and faint type Iax SNe exhibit distinct behaviour. Comparison with standard deflagration models suggests that SN 2018cni is consistent with the deflagration of a CO white dwarf whereas the properties of SN 2020kyg can be better explained by the deflagration of a hybrid CONe white dwarf. The spectral features of both the SNe point to the presence of similar chemical species but with different mass fractions. Our spectral modelling indicates stratification at the outer layers and mixed inner ejecta for both the SNe.

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Mridweeka Singh, Devendra. K. Sahu, Raya Dastidar, Barnabas Barna, Kuntal Misra, Anjasha Gangopadhyay, D. Andrew Howell, Saurabh W. Jha, Hyobin Im, Kirsty Taggart, Jennifer Andrews, Daichi Hiramatsu, Rishabh Singh Teja, Craig Pellegrino, Ryan J. Foley, Arti Joshi, G. C. Anupama, K. Azalee Bostroem, Jamison Burke, Yssavo Camacho-Neves, Anirban Dutta, Lindsey A. Kwok, Curtis McCully, Yen-Chen Pan, Matt Siebert, Shubham Srivastav, Tamas Szalai, Jonathan J. Swift, Grace Yang, Henry Zhou, Nico DiLullo, Jackson Scheer. 2023-05-22. Observational properties of a bright type Iax SN 2018cni and a faint type Iax SN 2020kyg. https://doi.org/10.3847/1538-4357%2Facd559

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