STUDY OF THE DETONATION PHASE IN THE GRAVITATIONALLY CONFINED DETONATION MODEL OF TYPE Ia SUPERNOVAE

We study the gravitationally confined detonation (GCD) model of Type Ia supernovae (SNe Ia) through the detonation phase and into homologous expansion. In the GCD model, a detonation is triggered by the surface flow due to single-point, off-center flame ignition in carbon-oxygen white dwarfs (WDs). The simulations are unique in terms of the degree to which nonidealized physics is used to treat the reactive flow, including weak reaction rates and a time-dependent treatment of material in nuclear statistical equilibrium (NSE). Careful attention is paid to accurately calculating the final composition of material which is burned to NSE and frozen out in the rapid expansion following the passage of a detonation wave over the high-density core of the WD; and an efficient method for nucleosynthesis postprocessing is developed which obviates the need for costly network calculations along tracer particle thermodynamic trajectories. Observational diagnostics are presented for the explosion models, including abundance stratifications and integrated yields. We find that for all of the ignition conditions studied here a self-regulating process comprised of neutronization and stellar expansion results in final 56Ni masses of ~1.1?M ?. But, more energetic models result in larger total NSE and stable Fe-peak yields. The total yield of intermediate mass elements is ~0.1?M ? and the explosion energies are all around 1.5 ? 1051 erg. The explosion models are briefly compared to the inferred properties of recent SN Ia observations. The potential for surface detonation models to produce lower-luminosity (lower 56Ni mass) SNe is discussed.

[1]  Iap Astrophysics Meeting,et al.  Advances in nuclear astrophysics , 1986 .

[2]  F. Timmes,et al.  TO APPEAR IN THE ASTROPHYSICAL JOURNAL LETTERS Preprint typeset using LATEX style emulateapj v. 3/3/03 ON VARIATIONS IN THE PEAK LUMINOSITY OF TYPE IA SUPERNOVAE , 2003 .

[3]  Elaine S. Oran,et al.  Multilevel Structure of Cellular Detonations in Type Ia Supernovae , 1999 .

[4]  K. Nomoto,et al.  The Role of Electron Captures in Chandrasekhar-Mass Models for Type Ia Supernovae , 2000, astro-ph/0001464.

[5]  S. E. Woosley,et al.  The conductive propagation of nuclear flames. I. Degenerate C+O and O+ Ne + Mg white dwarfs , 1992 .

[6]  D. Kasen,et al.  Spectropolarimetry of SN 2001el in NGC 1448: Asphericity of a Normal Type Ia Supernova , 2003, astro-ph/0303397.

[7]  A. Piro,et al.  Neutronization during Type Ia Supernova Simmering , 2007, 0710.1600.

[8]  W. Arnett,et al.  The delayed-detonation model of a type Ia supernovae. 1: The deflagration phase , 1994 .

[9]  B. Fryxell,et al.  On the Cellular Structure of Carbon Detonations , 2000 .

[10]  Nucleosynthesis in multi-dimensional SN Ia explosions , 2004, astro-ph/0406281.

[11]  W. Hillebrandt,et al.  A localised subgrid scale model for fluid dynamical simulations in astrophysics II: Application to , 2006, astro-ph/0601500.

[12]  Phillip Colella,et al.  Efficient Solution Algorithms for the Riemann Problem for Real Gases , 1985 .

[13]  B. Fryxell,et al.  FLASH: An Adaptive Mesh Hydrodynamics Code for Modeling Astrophysical Thermonuclear Flashes , 2000 .

[14]  Caltech,et al.  Flame Evolution During Type Ia Supernovae and the Deflagration Phase in the Gravitationally Confined Detonation Scenario , 2007, 0706.1094.

[15]  David Branch,et al.  IN SEARCH OF THE PROGENITORS OF TYPE IA SUPERNOVAE , 1995 .

[16]  P. Woodward,et al.  The Piecewise Parabolic Method (PPM) for Gas Dynamical Simulations , 1984 .

[17]  A localised subgrid scale model for fluid dynamical simulations in astrophysics I: Theory and numerical tests , 2006, astro-ph/0601499.

[18]  G. Martínez-Pinedo,et al.  RATE TABLES FOR THE WEAK PROCESSES OF pf-SHELL NUCLEI IN STELLAR ENVIRONMENTS , 2001 .

[19]  S. Woosley,et al.  The Explosive Burning of Oxygen and Silicon , 1973 .

[20]  D. García-Senz,et al.  Type Ia Supernova models arising from different distributions of igniting points , 2004, astro-ph/0409480.

[21]  Abundance stratification in Type Ia supernovae - I. The case of SN 2002bo , 2004, astro-ph/0409342.

[22]  J. Truran,et al.  Nuclear statistical equilibrium for Type Ia supernova simulations , 2009 .

[23]  G. Sharpe.  The effect of curvature on detonation waves in Type Ia supernovae , 2001 .

[24]  F. Timmes,et al.  The Accuracy, Consistency, and Speed of Five Equations of State for Stellar Hydrodynamics , 1999 .

[25]  Spectropolarimetric Diagnostics of Thermonuclear Supernova Explosions , 2006, Science.

[26]  D. García-Senz,et al.  Beyond the Bubble Catastrophe of Type Ia Supernovae: Pulsating Reverse Detonation Models , 2006, astro-ph/0604025.

[27]  S. E. Woosley,et al.  Carbon Ignition in Type Ia Supernovae: An Analytic Model , 2003, astro-ph/0307565.

[28]  University of Chicago,et al.  Type Ia Supernova Explosion: Gravitationally Confined Detonation , 2004 .

[29]  Tomasz Plewa,et al.  Detonating Failed Deflagration Model of Thermonuclear Supernovae. I. Explosion Dynamics , 2007 .

[30]  R. E. Casten,et al.  Nuclear Physics , 1935, Nature.

[31]  O. E. Bronson Messer,et al.  Capturing the Fire: Flame Energetics and Neutronization for Type Ia Supernova Simulations , 2006, The Astrophysical Journal.

[32]  S. Woosley,et al.  Presupernova evolution of massive stars. , 1978 .

[33]  K. Lodders.  Solar System Abundances and Condensation Temperatures of the Elements , 2003 .

[34]  S. Woosley,et al.  The Thermonuclear Explosion of Chandrasekhar Mass White Dwarfs , 1996, astro-ph/9607032.

[35]  E. Oran,et al.  Three-dimensional Delayed-Detonation Model of Type Ia Supernovae , 2004, astro-ph/0409598.

[36]  Paolo A. Mazzali,et al.  A Three-Dimensional Deflagration Model for Type Ia Supernovae Compared with Observations , 2007, 0707.1024.

[37]  A. Chtchelkanova,et al.  Thermonuclear Supernovae: Simulations of the Deflagration Stage and Their Implications , 2002, Science.

[38]  M. Phillips,et al.  Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant , 1998, astro-ph/9805201.

[39]  F. Thielemann,et al.  Astrophysical reaction rates from statistical model calculations , 2000, astro-ph/0004059.

[40]  D. Lamb,et al.  Three-Dimensional Simulations of the Deflagration Phase of the Gravitationally Confined Detonation Model of Type Ia Supernovae , 2007 .

[41]  Koichi Iwamoto,et al.  Nucleosynthesis in Chandrasekhar Mass Models for Type Ia Supernovae and Constraints on Progenitor Systems and Burning-Front Propagation , 1999 .

[42]  D. Branch,et al.  Detailed Spectral Modeling of a Three-dimensional Pulsating Reverse Detonation Model: Too Much Nickel , 2007, 0709.4177.

[43]  W. Hillebrandt,et al.  Type IA Supernova Explosion Models , 2000 .

[44]  Detonating Failed Deflagration Model of Thermonuclear Supernovae. II. Comparison to Observations , 2006, astro-ph/0612198.

[45]  F. Timmes,et al.  The Laminar Flame Speedup by 22Ne Enrichment in White Dwarf Supernovae , 2006, astro-ph/0612507.

[46]  F. Douglas Swesty,et al.  The Accuracy, Consistency, and Speed of an Electron-Positron Equation of State Based on Table Interpolation of the Helmholtz Free Energy , 2000 .

[47]  W. Fowler,et al.  Thermonuclear reaction rates V , 1988 .

[48]  Alexei M. Khokhlov,et al.  Propagation of Turbulent Flames in Supernovae , 1995 .

[49]  Garrett Birkhoff,et al.  Explosives with Lined Cavities , 1948 .

[50]  F. Timmes,et al.  The Reduction of the Electron Abundance during the Pre-explosion Simmering in White Dwarf Supernovae , 2008, 0801.1643.

[51]  J. Craig Wheeler,et al.  Deflagration-to-Detonation Transition in Thermonuclear Supernovae , 1996 .

[52]  Off-Center Ignition in Type Ia Supernovae. I. Initial Evolution and Implications for Delayed Detonation , 2006, astro-ph/0609088.