Three-dimensional pure deflagration models with nucleosynthesis and synthetic observables for Type Ia supernovae

TL;DR

This study uses 3D hydrodynamic models with nucleosynthesis and radiative transfer to explore pure deflagration scenarios in white dwarfs, aiming to explain certain subclasses of Type Ia supernovae, especially 2002cx-like events.

Contribution

It provides detailed 3D deflagration models with nucleosynthesis and synthetic observables, linking weak deflagrations to specific SN Ia subclasses and excluding highly ignited models for observed types.

Findings

Weak deflagrations produce bound remnants with 3-10% ashes.

Models with E_nuc ~ 0.5 x 10^51 erg fit 2002cx-like SNe Ia.

Brightest models are inconsistent with observed SN Ia colors and brightness.

Abstract

We investigate whether pure deflagration models of Chandrasekhar-mass carbon-oxygen white dwarf stars can account for one or more subclass of the observed population of Type Ia supernova (SN Ia) explosions. We compute a set of 3D full-star hydrodynamic explosion models, in which the deflagration strength is parametrized using the multispot ignition approach. For each model, we calculate detailed nucleosynthesis yields in a post-processing step with a 384 nuclide nuclear network. We also compute synthetic observables with our 3D Monte Carlo radiative transfer code for comparison with observations. For weak and intermediate deflagration strengths (energy release E_nuc <~ 1.1 x 10^51 erg), we find that the explosion leaves behind a bound remnant enriched with 3 to 10 per cent (by mass) of deflagration ashes. However, we do not obtain the large kick velocities recently reported in the literature. We find that weak deflagrations with E_nuc ~ 0.5 x 10^51 erg fit well both the light curves and spectra of 2002cx-like SNe Ia, and models with even lower explosion energies could explain some of the fainter members of this subclass. By comparing our synthetic observables with the properties of SNe Ia, we can exclude the brightest, most vigorously ignited models as candidates for any observed class of SN Ia: their B - V colours deviate significantly from both normal and 2002cx-like SNe Ia and they are too bright to be candidates for other subclasses.