Volume 478, Number 3, February II 2008
|Page(s)||843 - 853|
|Section||Stellar structure and evolution|
|Published online||12 December 2007|
A three-dimensional picture of the delayed-detonation model of type Ia supernovae
Departament de Física i Enginyeria Nuclear, UPC, Jordi Girona 3, Mòdul B5, 08034 Barcelona, Spain e-mail: firstname.lastname@example.org
2 Institut D'Estudis Espacials de Catalunya, Gran Capità 2-4, 08034 Barcelona, Spain e-mail: email@example.com
Accepted: 7 November 2007
Aims.Deflagration models poorly explain the observed diversity of SNIa. Current multidimensional simulations of SNIa predict a significant amount of, so far unobserved, carbon and oxygen moving at low velocities. It has been proposed that these drawbacks can be resolved if there is a sudden jump to a detonation (delayed detonation), but these kinds of models have been explored mainly in one dimension. Here we present new three-dimensional delayed detonation models in which the deflagraton-to-detonation transition (DDT) takes place in conditions like those favored by one-dimensional models.
Methods.We have used a smoothed-particle-hydrodynamics code adapted to follow all the dynamical phases of the explosion, with algorithms devised to handle subsonic as well as supersonic combustion fronts. The starting point was a centrally ignited C–O white dwarf of 1.38 . When the average density on the flame surface reached ~2-3107 g cm-3 a detonation was launched.
Results.The detonation wave processed more than 0.3 of carbon and oxygen, emptying the central regions of the ejecta of unburned fuel and raising its kinetic energy close to the fiducial 1051 erg expected from a healthy type Ia supernova. The final amount of 56Ni synthesized also was in the correct range. However, the mass of carbon and oxygen ejected is still too high.
Conclusions.The three-dimensional delayed detonation models explored here show an improvement over pure deflagration models, but they still fail to coincide with basic observational constraints. However, there are many aspects of the model that are still poorly known (geometry of flame ignition, mechanism of DDT, properties of detonation waves traversing a mixture of fuel and ashes). Therefore, it will be worth pursuing its exploration to see if a good SNIa model based on the three-dimensional delayed detonation scenario can be obtained.
Key words: hydrodynamics / nuclear reactions, nucleosynthesis, abundances / shock waves / stars: evolution / white dwarfs / supernovae: general
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.