Abstract
Sub-Chandrasekhar mass white dwarfs accreting a helium shell on a
carbon-oxygen core are potential progenitors of normal Type Ia
supernovae. This work focuses on the details of the onset of the carbon
detonation in the double detonation sub-Chandrasekhar model. In order to
simulate the influence of core-shell mixing on the carbon ignition
mechanism, the helium shell and its detonation are followed with an
increased resolution compared to the rest of the star treating the
propagation of the detonation wave more accurately. This significantly
improves the predictions of the nucleosynthetic yields from the helium
burning. The simulations were carried out with the AREPO code. A
carbon-oxygen core with a helium shell was set up in one dimension and
mapped to three dimensions. We ensured the stability of the white dwarf
with a relaxation step before the hydrodynamic detonation simulation
started. Synthetic observables were calculated with the radiative
transfer code ARTIS. An ignition mechanism of the carbon detonation was
observed, which received little attention before. In this "scissors
mechanism", the impact the helium detonation wave has on unburnt
material when converging opposite to its ignition spot is strong enough
to ignite a carbon detonation. This is possible in a carbon enriched
transition region between the core and shell. The detonation mechanism
is found to be sensitive to details of the core-shell transition and our
models illustrate the need to consider core-shell mixing taking place
during the accretion process. Even though the detonation ignition
mechanism differs form the converging shock mechanism, the differences
in the synthetic observables are not significant. Though they do not fit
observations better than previous simulations, they illustrate the need
for multi-dimensional simulations.
Original language | English |
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Number of pages | 18 |
Journal | Astronomy & Astrophysics |
Volume | 635 |
DOIs | |
Publication status | Published - 01 Mar 2020 |
Keywords
- hydrodynamics
- methods: numerical
- nuclear reactions
- nucleosynthesis
- abundances
- radiative transfer
- supernovae: general
- white dwarfs
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Dive into the research topics of 'SNe Ia from double detonations: Impact of core-shell mixing on the carbon ignition mechanism'. Together they form a unique fingerprint.Student theses
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Multi-dimensional Monte Carlo radiative transfer simulations: Investigating the double detonation scenario for type Ia supernovae
Collins, C. (Author), Sim, S. (Supervisor) & Smartt, S. (Supervisor), Jul 2021Student thesis: Doctoral Thesis › Doctor of Philosophy
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