The interaction of Type Iax supernova ejecta with a helium companion star

TL;DR

This study uses 3D hydrodynamical simulations to show that the amount of helium stripped from a companion star in Type Iax supernovae is consistent with observational non-detections, supporting the weak deflagration explosion model.

Contribution

It provides the first detailed 3D simulation of helium stripping in SNe Iax progenitors, linking theoretical predictions with observational constraints.

Findings

Approximately 0.004 solar masses of helium can be stripped.

Stripped helium mass aligns with observational upper limits.

Supports weak deflagration explosion models for SNe Iax.

Abstract

Type Iax supenovae (SNe Iax) are an important sub-luminous class of SNe Ia. However, their progenitors and explosion mechanism have not been understood yet. It has been suggested that SNe Iax may be produced from weak deflagration explosions of Chandrasekhar-mass white dwarfs (WDs) in binary systems with a helium (He) star donor. In such progenitor systems, the stripped He companion material caused by the ejecta-companion interaction is expected to present some He features in their late-time spectra. However, the detection of He lines in late-time spectra of SNe Iax has not yet been successful, which gives an upper limit on the amount of stripped He mass of < 0.002-0.1 solar masses. In this work, we study the interaction between SN Iax ejecta and a He star companion by performing three-dimensional hydrodynamical simulations with a weak pure deflagration explosion model. We find that about 0.004 solar masses of He material can be stripped off from the companion star by SN explosion, which is very close to (or lower than) the observational upper-limit on the total stripped He mass in SNe Iax. We, therefore, conclude that non-detection of He lines in late-time spectra of SNe Iax could be reasonably explained if they are indeed resulted from weak pure deflagration explosions of Chandrasekhar-mass WDs in progenitor systems with a He star donor.