The impact of type Ia supernovae on main sequence binary companions

TL;DR

This study uses simulations to show that the amount of hydrogen stripped from main sequence companions in Type Ia supernovae is low enough to keep the single-degenerate scenario consistent with observations.

Contribution

It demonstrates that realistic, more compact companion star models significantly reduce hydrogen stripping, supporting the viability of the single-degenerate progenitor scenario.

Findings

Reduced hydrogen stripping with realistic companion models

Simulation results align with observational constraints

Supports single-degenerate scenario validity

Abstract

The nature of Type Ia supernova progenitors is still unclear. The outstanding characteristic of the single-degenerate scenario is that it contains hydrogen in the binary companion of the exploding white dwarf star, which, if mixed into the ejecta of the supernova in large amounts may lead to conflicts with the observations thus ruling out the scenario. We investigate the effect of the impact of Type Ia supernova ejecta on a main sequence companion star of the progenitor system. With a series of simulations we investigate how different parameters of this system affect the amount of hydrogen stripped from the companion by the impact. The stellar evolution code GARSTEC is used to set up the structure of the companion stars mimicking the effect of a binary evolution phase. The impact itself is simulated with the smoothed particle hydrodynamics code GADGET2. We reproduce and confirm the results of earlier grid-based hydrodynamical simulation. Parameter studies of the progenitor system are extended to include the results of recent binary evolution studies. The more compact structure of the companion star found here significantly reduces the stripped hydrogen mass. The low hydrogen masses resulting from a more realistic companion structure are consistent with current observational constraints. Therefore, the single-degenerate scenario remains a valid possibility for Type Ia supernova progenitors. These new results are not a numerical effect, but the outcome of different initial conditions.