Type Ia supernova explosion models are inherently multidimensional

• Main Authors: Pakmor, R, Seitenzahl, I. R, Ruiter, A. J, Sim, S. A, Roepke, F. K, Taubenberger, S, Bieri, R, Blondin, S
• Format: Journal Article
• Language: English
• Published: 26-04-2024
• Subjects: Physics - High Energy Astrophysical Phenomena
• DOI: 10.48550/arxiv.2402.11010

A&A 686, A227 (2024) Theoretical and observational approaches to settling the important questions
surrounding the progenitor systems and the explosion mechanism of normal Type
Ia supernovae have thus far failed. With its unique capability to obtain
continuous spectra through the near- and mid-infrared, JWST now offers
completely new insights into Type Ia supernovae. In particular, observing them
in the nebular phase allows us to directly see the central ejecta and thereby
constrain the explosion mechanism. We aim to understand and quantify
differences in the structure and composition of the central ejecta of various
Type Ia supernova explosion models. We examined the currently most popular
explosion scenarios using self-consistent multidimensional explosion
simulations of delayed-detonation and pulsationally assisted, gravitationally
confined delayed detonation Chandrasekhar-mass models and double-detonation
sub-Chandrasekhar-mass and violent merger models. We find that the distribution
of radioactive and stable nickel in the final ejecta, both observable in
nebular spectra, are significantly different between different explosion
scenarios. Therefore, comparing synthetic nebular spectra with JWST
observations should allow us to distinguish between explosion models. We show
that the explosion ejecta are inherently multidimensional for all models, and
the Chandrasekhar-mass explosions simulated in spherical symmetry in particular
lead to a fundamentally unphysical ejecta structure. Moreover, we show that
radioactive and stable nickel cover a significant range of densities at a fixed
velocity of the homologously expanding ejecta. Any radiation transfer
postprocessing has to take these variations into account to obtain faithful
synthetic observables; this will likely require multidimensional radiation
transport simulations.