The effect of aspherical stellar wind of giant stars on the symbiotic channel of type Ia supernovae

TL;DR

This study models how aspherical stellar winds from giant stars in symbiotic systems influence the circumstellar medium's structure, impacting the observable signatures of Type Ia supernovae progenitors.

Contribution

It introduces a simplified method to estimate the density and shape of circumstellar material considering binary interactions and stellar wind asymmetry in symbiotic systems.

Findings

SNe Ia can originate from symbiotic systems with massive CO white dwarfs.

The wind's half-opening angle varies with binary evolution, affecting CSM geometry.

Ejecta-CSM interaction properties can be probed by spectropolarimetry in future observations.

Abstract

The progenitor systems accounting for explosions of type Ia supernovae (SNe Ia) is still under debate. Symbiotic channel is one of the possible progenitor scenarios, in which the WDs in these systems increase in mass through wind accretion from their red giant companions. The mass-loss processes of the giants in the symbiotic systems could produce amount of circumstellar medium (CSM), and the detections of the interaction signals between SN ejecta and CSM can be used as an ideal way to distinguish the different progenitor models. However, the density distribution and geometric structure of the CSM around the symbiotic systems remain highly uncertain. By assuming that the tidal torque from binary interaction can increase the mass-loss rate of the red giant and cause the stellar wind concentrate towards the equatorial plane, we provide a simplified method to estimate the density and the degree of deviation from spherical symmetry of the CSM. Based on the calculations of the binary evolutions of symbiotic systems using stellar evolution code MESA, we obtained the parameter space for producing SNe Ia. We found that SNe Ia could originate from symbiotic systems with massive carbon-oxygen white dwarfs (CO WDs), while the half-opening angle of the stellar wind from red giant towards the WD varies with the binary evolution, resulting in the formation of surrounding CSM with different geometric structures. The corresponding properties of ejecta-CSM interactions may be examined by the spectropolarimetry observations in the future, from which one may find additional relationship between circumstellar environment of SNe Ia and their progenitor systems.