Constraints on single-degenerate Chandrasekhar mass progenitors of Type Iax supernovae

TL;DR

This paper investigates the viability of single-degenerate Chandrasekhar mass progenitors for Type Iax supernovae by comparing theoretical models with observations, finding some channels plausible but unlikely to be the dominant source.

Contribution

It provides constraints on the single-degenerate Chandrasekhar mass model for SNe Iax using binary population synthesis and observational data.

Findings

Long delay times in the RG donor channel make it unlikely to produce SNe Iax.

Galactic rate predictions for MS and He donor channels align with observed Iax rates.

Current observations cannot rule out the SD Ch-mass model as a progenitor scenario.

Abstract

SNe Iax are proposed as one new sub-class of SNe Ia. SNe Iax have been estimated to account for ~5-30% of the total SN Ia rate, and most SNe Iax have been discovered in late-type galaxies. In addition, observations constrain the progenitor systems of some SN Iax progenitors have ages of <80Myr. Recently, the weak deflagration explosions of Ch-mass CO WDs seem to provide a viable physical scenario for SNe Iax. Here, comparing theoretical predictions from BPS calculations with SN Iax observations, we put constraints on the SD Ch-mass model as a possible Iax progenitor. A long delay times of >3Gyr and low SN rates of ~3e-5/yr are found in our RG donor channel, indicating that this channel is unlikely to produce SNe Iax. We predict that the Galactic rate from the MS (He) donor channel is ~1.5e-3/yr (3e-4/yr), which is consistent with the observed Iax rate. The short delay times in the He channel support the young host environments of SNe Iax. However, the relative long delay times in the MS donor channel are less favourable for the observational constraints on the Iax progenitor ages. Finally, we set an upper limit on the pre-SN mass-loss rate at < 10e-4 M_sun/yr (for V_wind=100 km/s). The delay times in the SD Ch-mass model do not account for that most SNe Iax are located in late-type galaxies. However, at least one Iax event (SN 2008ge) is hosted by a S0 galaxy with no signs of star formation. Moreover, current X-ray observations cannot rule out the SD Ch-mass model. Taking all these into account and considering the uncertainty of the observed rate for SNe Iax, we suggest that some SNe Iax may be produced from weak deflagrations of Ch-mass CO WDs in SD progenitors, especially in the He-star channel. This is consistent with recent analysis of HST observations for the SN Iax SN2012Z. However, this SD deflagration model is still unlikely to be the most common progenitor scenario for SNe Iax.