Spectra of Type Ia Supernovae from Double Degenerate Mergers

TL;DR

This paper investigates whether double degenerate white dwarf mergers can produce type Ia supernovae, analyzing their light-curves and spectral features to compare with observations and explore potential reconciliation.

Contribution

It combines population synthesis, merger, explosion, and radiation-hydrodynamics models to assess the viability of double degenerate mergers as type Ia supernova progenitors.

Findings

Produced broader light-curves than observed supernovae

Identified differences in shock breakout and spectral features

Discussed potential ways to reconcile models with observations

Abstract

The merger of two white dwarfs (a.k.a. double degenerate merger) has often been cited as a potential progenitor of type Ia supernovae. Here we combine population synthesis, merger and explosion models with radiation-hydrodynamics light-curve models to study the implications of such a progenitor scenario on the observed type Ia supernova population. Our standard model, assuming double degenerate mergers do produce thermonuclear explosions, produces supernova light-curves that are broader than the observed type Ia sample. In addition, we discuss how the shock breakout and spectral features of these double degenerate progenitors will differ from the canonical bare Chandrasekhar-massed explosion models. We conclude with a discussion of how one might reconcile these differences with current observations.