Common continuum polarization properties: a possible link between proto-planetary nebulae and Type Ia Supernovae progenitors

TL;DR

This paper investigates the polarization properties of proto-planetary nebulae and their potential connection to Type Ia supernova progenitors, suggesting some SNe Ia may originate from post-AGB binary systems.

Contribution

It identifies similarities in polarization curves between PPNe and SNe Ia, proposing a link and supporting the core-degenerate progenitor model.

Findings

PPNe exhibit polarization curves similar to SNe Ia.

Circumstellar dust scattering explains the polarization features.

Some SNe Ia may explode during the post-AGB phase.

Abstract

The lines-of-sight to highly reddened SNe Ia show peculiar continuum polarization curves, growing toward blue wavelengths and peaking at $\lambda_{max} \lesssim 0.4 \mu m$, like no other sight line to any normal Galactic star. We examined continuum polarization measurements of a sample of asymptotic giant branch (AGB) and post-AGB stars from the literature, finding that some PPNe have polarization curves similar to those observed along SNe Ia sight lines. Those polarization curves are produced by scattering on circumstellar dust. We discuss the similarity and the possibility that at least some SNe Ia might explode during the post-AGB phase of their binary companion. Furthermore, we speculate that the peculiar SNe Ia polarization curves might provide observational support to the core-degenerate progenitor model.