Three-dimensional delayed-detonation models with nucleosynthesis for Type Ia supernovae

TLDR

The study aims to provide a database of Chandrasekhar‑mass delayed‑detonation model nucleosynthetic yields for generating synthetic spectra and light curves. The authors performed 14 high‑resolution 3D delayed‑detonation simulations of Chandrasekhar‑mass white dwarfs, using a stochastic turbulent model to set deflagration‑to‑detonation transition probabilities, varying ignition kernels and central densities, and post‑processing tracer particles with a 384‑nuclide network to compute detailed nucleosynthetic yields. The simulations, the first 3D SN Ia models with detailed isotopic yields, unbind the white dwarf and produce 56Ni masses between 0.32 and 1.11 M⊙, with neutron‑rich iron‑group isotopes concentrated at intermediate velocities and low‑velocity oxygen and carbon.

Abstract

We present results for a suite of 14 three-dimensional, high-resolution hydrodynamical simulations of delayed-detonation models of Type Ia supernova (SN Ia) explosions. This model suite comprises the first set of three-dimensional SN Ia simulations with detailed isotopic yield information. As such, it may serve as a data base for Chandrasekhar-mass delayed-detonation model nucleosynthetic yields and for deriving synthetic observables such as spectra and light curves. We employ a physically motivated, stochastic model based on turbulent velocity fluctuations and fuel density to calculate in situ the deflagration-to-detonation transition probabilities. To obtain different strengths of the deflagration phase and thereby different degrees of pre-expansion, we have chosen a sequence of initial models with 1, 3, 5, 10, 20, 40, 100, 150, 200, 300 and 1600 (two different realizations) ignition kernels in a hydrostatic white dwarf with a central density of 2.9 × 109 g cm−3, as well as one high central density (5.5 × 109 g cm−3) and one low central density (1.0 × 109 g cm−3) rendition of the 100 ignition kernel configuration. For each simulation, we determined detailed nucleosynthetic yields by post-processing 106 tracer particles with a 384 nuclide reaction network. All delayed-detonation models result in explosions unbinding the white dwarf, producing a range of 56Ni masses from 0.32 to 1.11 M⊙. As a general trend, the models predict that the stable neutron-rich iron-group isotopes are not found at the lowest velocities, but rather at intermediate velocities (∼3000–10 000 km s−1) in a shell surrounding a 56Ni-rich core. The models further predict relatively low-velocity oxygen and carbon, with typical minimum velocities around 4000 and 10 000 km s−1, respectively.