Speaker
Description
Thermonuclear supernovae are key sites of explosive nucleosynthesis, playing a central role in shaping the isotopic composition of galaxies and contributing significantly to Fe-group and intermediate-mass elements. While Type Ia supernovae are traditionally associated with thermonuclear explosions in binary star systems, recent theoretical work (Antoniadis et al. 2020) challenges this paradigm by suggesting that thermonuclear supernovae may also arise from non-accreting single-star progenitors. If substantiated, this alternative channel could potentially influence the thermonuclear supernovae rate in star-forming galaxies.
To further explore this hypothesis, in this study we build on the 1D stellar evolution models from Antoniadis et al. (2020), and we extend the investigation to 3D simulations of the explosion phase, to rigorously examine the dynamics and nucleosynthetic yields in dense oxygen–neon cores.
The precise isotopic composition of these events remains largely unconstrained. To address this, we use our simulations to track nuclear reactions throughout the explosion and then post-process the results with a detailed nuclear network using the NuGrid tools to obtain detailed isotopic abundances. This study presents the estimates of their isotopic yields. Building on these, we present the first early-time synthetic spectra for this explosion channel, providing direct, testable observational diagnostics.
This analysis is imperative for constraining the frequency of such thermonuclear events and facilitates the generation of state-of-the-art synthetic observables. The findings will play a pivotal role in assessing the viability of single-star thermonuclear explosions as a natural contributor to the observed thermonuclear supernovae population.