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Outline

Outline. Introducing thermonuclear supernovae. Scales: time, space & physics . Many sins of turbulent deflagrations. Foreplay counts: forgotten tale of the ICs. Detonating Failed Deflagrations. Confronting DFD with observations. Summary. What Are Supernovae?. Massive and Even More Massive.

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Outline

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  1. Outline Introducing thermonuclear supernovae Scales: time, space & physics Many sins of turbulent deflagrations Foreplay counts: forgotten tale of the ICs Detonating Failed Deflagrations Confronting DFD with observations Summary

  2. What Are Supernovae?

  3. Massive and Even More Massive Type II Massive Single H-rich Type Ia Medium mass Binary H/He-free

  4. Type Ia SN Appearance P. Nugent (LBNL)

  5. Why Do We Care? • SN Ia are crucial for galactic chemical evolution. • SN Ia are also crucial for cosmology: probes allowing study of expansion and geometry (M, ) of the Universe, nature of dark energy • Provide astrophysical setting for basic combustion problems. COBE High-Z Supernova Search Team, HST

  6. 40 Years of Theory 1960s • WD explosion proposed for Type Ia (Hoyle & Fowler) • 1D detonation model (Arnett) 1970s • detonation models (several groups) • deflagration models (Nomoto) 1980s • improved 1-D deflagration models (Nomoto) • first 2-D deflagration model (Mueller & Arnett) 1990s • 2-D and 3-D deflagration models, DDT (Khokhlov) • non-standard models 2-D He detonations (Livne & Arnett) • small scale flame turbulence (Niemeyer & Hillebrandt) 2000s • 3-D deflagration models (NRL, MPA, Barcelona, Chicago) • 3-D DDT models (NRL)

  7. Problem Parameters Channels for progenitors • Binary evolution • Population synthesis Initial conditions • State of the stellar core • Metallicity • Rotation profile • Magnetic fields Basic physics • Flame on intermediate scales • Unsteadiness • DDT Numerics • Multiphysics coupling • Nucleosynthesis postprocessing R. Hynes INCITE 2004 F. Timmes Zhang et al. (2006) Khokhlov (2003)

  8. Explosive Stage of SN Ia 102/4-7 cm mild ignition 1010 seconds deeply subsonic, Ma ~ 10-4 10-3/5-8 cm few seconds deflagration subsonic: Ma ~ 0.3 101/5-8 cm detonation 0.5 second compressible: Ma ~ 2

  9. Why Large Scale Simulations? Khokhlov (2003)

  10. RT-driven Turbulence Zhang et al. (2006)

  11. Major Sins of Classic Central Deflagrations 1. Uniformly mixed ejecta, unburned low-velocity carbon 2. Explosion energies too low, need ~50% more burning 3. Initial conditions either too idealized or defined ad hoc 4. Large Ni-rich structures visible at maximum light 5. Insufficient production of intermediate mass elements

  12. Central Ignition Whole Star Model INCITE 2004 • Two models, 255,000 SUs and 5TB of data per model, 8 km resolution

  13. Ejecta Composition: Pure Deflagrations • Ni C/O • Si • Mg Gamezo et al. (2003) Reinecke et al. (2002) Roepke et al. (2005) Garcia-Senz & Bravo (2004)

  14. Stratification, Energy: Speculative DDT • 3-D pure deflagration • 3-D speculative DDT Gamezo et al. (2003)

  15. Initial Conditions Garcia-Senz & Woosley (1995) Hoeflich & Stein (2002) Kuhlen, Woosley, & Glatzmeier (2005)

  16. Single Bubble, Three Different Methods… 2-D 2-D Livne, Asida, & Hoeflich (2005) 3-D Niemeyer, Hillebrandt, & Woosley (1996) …and virtually the same result! Calder et al. (2004)

  17. Initial Conditions: Location, Velocity Field r1y100v100a3030in (inflowing, 100 km/s) INCITE 2004

  18. Initial Conditions: Conclusion Garcia-Senz & Woosley (1995) Hoeflich & Stein (2002) Woosley, Wunsch, & Kuhlen (2004) Calder et al. (2004) Livne, Asida, & Hoeflich (2005) Kuehlen, Woosley, & Glatzmeier (2005) Based on analytic, semi-analytic, and numerical models, the most likely outcome of a mild ignition is the off-center deflagration.

  19. Detonating Failed Deflagration

  20. DFD Detonation Phase

  21. Double-bubble DFD

  22. Double-bubble DFD at 1 km resolution

  23. Model Validation – Radiative Transfer Kasen, Thomas, & Nugent (2006): Multi-dimensional time-dependent Monte Carlo radiative transfer

  24. Model Validation – Radiative Transfer Kasen, Thomas, & Nugent (2006): Multi-dimensional time-dependent Monte Carlo radiative transfer

  25. Overall Spectrum Shape DFD at 18 days vs. SN1981B at maximum light.

  26. DFD/W7 At Maximum Light

  27. Velocity Evolution Orientation effects controlled by the deflagration phase in the DFD model Benetti et al. (2005)

  28. Distribution of IME in DFD

  29. GCD Spectral Signatures Kasen & Plewa (2005)

  30. Tycho SNR Iron Distribution FS RS ??? Warren et al. (2005)

  31. Summary • Detonating Failed Deflagration • displays several main characteristics of observed objects • energetics, light curves, spectra/spectral features • emphasized importance of the initial conditions • detonation in unconfined environment • natural chain of events, not by-hand, but from first principles • Extremely rare case in theoretical astrophysics! To be continued!

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