NUCLEOSYNTHESIS IN TWO-DIMENSIONAL DELAYED DETONATION MODELS OF TYPE Ia SUPERNOVA EXPLOSIONS

Journal Article · Sat Mar 20 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/712/1/624· OSTI ID:21394241

Maeda, K ^[1]; Roepke, F K; Fink, M; Hillebrandt, W; Travaglio, C ^[2]

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1. Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan)
2. Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, 85741 Garching (Germany)

For the explosion mechanism of Type Ia supernovae (SNe Ia), different scenarios have been suggested. In these, the propagation of the burning front through the exploding white dwarf (WD) star proceeds in different modes, and consequently imprints of the explosion model on the nucleosynthetic yields can be expected. The nucleosynthetic characteristics of various explosion mechanisms are explored based on three two-dimensional explosion simulations representing extreme cases: a pure turbulent deflagration, a delayed detonation following an approximately spherical ignition of the initial deflagration, and a delayed detonation arising from a highly asymmetric deflagration ignition. Apart from this initial condition, the deflagration stage is treated in a parameter-free approach. The detonation is initiated when the turbulent burning enters the distributed burning regime. This occurs at densities around 10{sup 7} g cm{sup -3}-relatively low as compared to existing nucleosynthesis studies for one-dimensional spherically symmetric models. The burning in these multidimensional models is different from that in one-dimensional simulations as the detonation wave propagates both into unburned material in the high-density region near the center of a WD and into the low-density region near the surface. Thus, the resulting yield is a mixture of different explosive burning products, from carbon-burning products at low densities to complete silicon-burning products at the highest densities, as well as electron-capture products synthesized at the deflagration stage. Detailed calculations of the nucleosynthesis in all three models are presented. In contrast to the deflagration model, the delayed detonations produce a characteristic layered structure and the yields largely satisfy constraints from Galactic chemical evolution. In the asymmetric delayed detonation model, the region filled with electron capture species (e.g., {sup 58}Ni, {sup 54}Fe) is within a shell, showing a large off-set, above the bulk of {sup 56}Ni distribution, while species produced by the detonation are distributed more spherically.

• OSTI ID: 21394241
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 712; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BINARY STARS
CAPTURE
CARBON BURNING
CONFIGURATION
DAYS LIVING RADIOISOTOPES
DENSITY
DETONATION WAVES
DWARF STARS
ELECTRON CAPTURE
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ERUPTIVE VARIABLE STARS
EVEN-EVEN NUCLEI
EVOLUTION
EXPLOSIONS
FLUID MECHANICS
GALACTIC EVOLUTION
HYDRODYNAMICS
INTERMEDIATE MASS NUCLEI
IRON 54
IRON ISOTOPES
ISOTOPES
MECHANICS
NICKEL 56
NICKEL 58
NICKEL ISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUCLEOSYNTHESIS
ONE-DIMENSIONAL CALCULATIONS
PHYSICAL PROPERTIES
RADIOISOTOPES
SEMIMETALS
SHOCK WAVES
SILICON
SIMULATION
SPHERICAL CONFIGURATION
STABLE ISOTOPES
STAR BURNING
STARS
SUPERNOVAE
SYNTHESIS
TWO-DIMENSIONAL CALCULATIONS
VARIABLE STARS
WHITE DWARF STARS