Thermonuclear Supernova: A Successful Failure

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(No Transcript)
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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
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What Are Supernovae?
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Massive and Even More Massive
Type II Massive Single H-rich
Type Ia Medium mass Binary H/He-free
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Type Ia SN Appearance
P. Nugent (LBNL)
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Why Do We Care?
COBE

• 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.

High-Z Supernova Search Team, HST
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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)

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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)
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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
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Why Large Scale Simulations?
Khokhlov (2003)
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RT-driven Turbulence
Zhang et al. (2006)
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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
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Central Ignition Whole Star Model
INCITE 2004

• Two models, 255,000 SUs and 5TB of data per
  model, 8 km resolution

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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)
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Stratification, Energy Speculative DDT

• 3-D pure deflagration

• 3-D speculative DDT

Gamezo et al. (2003)
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Initial Conditions
Garcia-Senz Woosley (1995)
Hoeflich Stein (2002)
Kuhlen, Woosley, Glatzmeier (2005)
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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)
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Initial Conditions Location, Velocity Field
r1y100v100a3030in (inflowing, 100 km/s)
INCITE 2004
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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.
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Detonating Failed Deflagration
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DFD Detonation Phase
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Double-bubble DFD
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Double-bubble DFD at 1 km resolution
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Model Validation Radiative Transfer
Kasen, Thomas, Nugent (2006) Multi-dimensional
time-dependent Monte Carlo radiative transfer
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Model Validation Radiative Transfer
Kasen, Thomas, Nugent (2006) Multi-dimensional
time-dependent Monte Carlo radiative transfer
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Overall Spectrum Shape
DFD at 18 days vs. SN1981B at maximum light.
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DFD/W7 At Maximum Light
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Velocity Evolution
Orientation effects controlled by the
deflagration phase in the DFD model
Benetti et al. (2005)
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Distribution of IME in DFD
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GCD Spectral Signatures
Kasen Plewa (2005)
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Tycho SNR Iron Distribution
FS
RS
???
Warren et al. (2005)
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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!