EVALUATING SYSTEMATIC DEPENDENCIES OF TYPE Ia SUPERNOVAE: THE INFLUENCE OF DEFLAGRATION TO DETONATION DENSITY

Journal Article · Wed Sep 01 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/720/1/99· OSTI ID:21460159

Jackson, Aaron P; Calder, Alan C ^[1]; Townsley, Dean M ^[2]; Chamulak, David A ^[3]; Brown, Edward F; Timmes, F X ^[4]

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1. Department of Physics and Astronomy, State University of New York-Stony Brook, Stony Brook, NY (United States)
2. Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL (United States)
3. Argonne National Laboratory, Argonne, IL (United States)
4. Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)

We explore the effects of the deflagration to detonation transition (DDT) density on the production of {sup 56}Ni in thermonuclear supernova (SN) explosions (Type Ia supernovae). Within the DDT paradigm, the transition density sets the amount of expansion during the deflagration phase of the explosion and therefore the amount of nuclear statistical equilibrium (NSE) material produced. We employ a theoretical framework for a well-controlled statistical study of two-dimensional simulations of thermonuclear SNe with randomized initial conditions that can, with a particular choice of transition density, produce a similar average and range of {sup 56}Ni masses to those inferred from observations. Within this framework, we utilize a more realistic 'simmered' white dwarf progenitor model with a flame model and energetics scheme to calculate the amount of {sup 56}Ni and NSE material synthesized for a suite of simulated explosions in which the transition density is varied in the range (1-3) x10{sup 7} g cm{sup -3}. We find a quadratic dependence of the NSE yield on the log of the transition density, which is determined by the competition between plume rise and stellar expansion. By considering the effect of metallicity on the transition density, we find the NSE yield decreases by 0.055 {+-} 0.004 M {sub sun} for a 1 Z{sub sun} increase in metallicity evaluated about solar metallicity. For the same change in metallicity, this result translates to a 0.067 {+-} 0.004 M{sub sun} decrease in the {sup 56}Ni yield, slightly stronger than that due to the variation in electron fraction from the initial composition. Observations testing the dependence of the yield on metallicity remain somewhat ambiguous, but the dependence we find is comparable to that inferred from some studies.

• OSTI ID: 21460159
• Journal Information: Astrophysical Journal, Vol. 720, Issue 1; Other Information: DOI: 10.1088/0004-637X/720/1/99; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABUNDANCE
ASTROPHYSICS
EXPLOSIONS
HYDRODYNAMICS
NEUTRON SPECTROSCOPY
NICKEL 56
NUCLEAR REACTIONS
NUCLEOSYNTHESIS
SIMULATION
SPIN ECHO
SUPERNOVAE
WHITE DWARF STARS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BINARY STARS
DAYS LIVING RADIOISOTOPES
DWARF STARS
ELECTRON CAPTURE RADIOISOTOPES
ERUPTIVE VARIABLE STARS
EVEN-EVEN NUCLEI
FLUID MECHANICS
INTERMEDIATE MASS NUCLEI
ISOTOPES
MECHANICS
NICKEL ISOTOPES
NUCLEI
PHYSICS
RADIOISOTOPES
SPECTROSCOPY
STARS
SYNTHESIS
VARIABLE STARS