SN 2020kyg and the rates of faint Iax supernovae from ATLAS

We present multiwavelength follow-up observations of the ATLAS discovered faint Iax supernova SN 2020kyg that peaked at an absolute magnitude of Mg ≈-14.9 ± 0.2, making it another member of the faint Iax supernova population. The bolometric light curve requires only ≈7 × 10-3 M· of radioactive 56Ni, with an ejected mass of Mej ∼0.4 M· and a low kinetic energy of E ≈ 0.05 ± 0.02 × 1051 erg. We construct a homogeneous volume-limited sample of 902 transients observed by ATLAS within 100 Mpc during a 3.5 yr span. Using this sample, we constrain the rates of faint Iax (Mr ≳-16) events within 60 Mpc at 12+14-8 per cent of the SN Ia rate. The overall Iax rate, at 15+17-9 per cent of the Ia rate, is dominated by the low-luminosity events, with luminous SNe Iax (Mr ≲-17.5) like 2002cx and 2005hk, accounting for only 0.9+1.1-0.5 per cent of the Ia rate (a 2σ upper limit of approximately 3 per cent). We favour the hybrid CONe WD + He star progenitor channel involving a failed deflagration of a near Chandrasekhar mass white dwarf, expected to leave a bound remnant and a surviving secondary companion, as a candidate explanation for faint Iax explosions. This scenario requires short delay times, consistent with the observed environments of SNe Iax. Furthermore, binary population synthesis calculations have suggested rates of 1-18 per cent of the SN Ia rate for this channel, consistent with our rate estimates. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.

Notas

Indexación: Scopus.

Palabras clave

Supernovae: general, Supernovae: individual: SN 2020kyg, Combustion, Kinetic energy, Kinetics, White dwarfs

Citación

Monthly Notices of the Royal Astronomical Society, Volume 511, Issue 2, Pages 2708 - 2731, 1 April 2022

DOI

10.1093/mnras/stac177

URI

https://repositorio.unab.cl/handle/ria/58432

Colecciones

FCE - Artículos de Revista

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