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

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