Three-dimensional Simulations of Pure Deflagration Models for Thermonuclear Supernovae

TL;DR

This study uses 3D simulations to explore pure deflagration models of Type Ia supernovae, revealing how initial ignition conditions influence explosion characteristics and their resemblance to under-luminous SNe Iax.

Contribution

It systematically investigates how varying initial ignition parameters affect the outcomes of pure deflagration supernova models using high-resolution 3D simulations.

Findings

Fewer ignition points lead to more energetic explosions and resemble under-luminous SNe Iax.

The number of ignition points significantly influences the distribution of nucleosynthetic products.

Simulations with many ignition points do not resemble under-luminous SNe Iax.

Abstract

We present a systematic study of the pure deflagration model of Type Ia supernovae using three-dimensional, high-resolution, full-star hydrodynamical simulations, nucleosynthetic yields calculated using Lagrangian tracer particles, and light curves calculated using radiation transport. We evaluate the simulations by comparing their predicted light curves with many observed SNe Ia using the SALT2 data-driven model and find that the simulations may correspond to under-luminous SNe Iax. We explore the effects of the initial conditions on our results by varying the number of randomly selected ignition points from 63 to 3500, and the radius of the centered sphere they are confined in from 128 to 384 km. We find that the rate of nuclear burning depends on the number of ignition points at early times, the density of ignition points at intermediate times, and the radius of the confining sphere at late times. The results depend primarily on the number of ignition points, but we do not expect this to be the case in general. The simulations with few ignition points release more nuclear energy $E_{\mathrm{nuc}}$, have larger kinetic energies $E_{\mathrm{K}}$, and produce more $^{56}$Ni than those with many ignition points, and differ in the distribution of $^{56}$Ni, Si, and C/O in the ejecta. For these reasons, the simulations with few ignition points exhibit higher peak B-band absolute magnitudes $M_\mathrm{B}$ and light curves that rise and decline more quickly; their $M_\mathrm{B}$ and light curves resemble those of under-luminous SNe Iax, while those for simulations with many ignition points are not.