1 1 physics of type ia supernova explosions a. khokhlov, a.poludnenko (the university of chicago)...
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Physics of Type Ia Supernova Explosions
A. Khokhlov,A.Poludnenko
(The University of Chicago)Lifan Wang
(A&M)P. Hoeflich(U Florida)
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Carbon-Oxygen White Dwarf Exploding as a SNIa.
R=2.108cm
Mass ~ 2.8 1033 g Temperatures ~ 3 – 9 109KDensity ~ 2.0 109 g/cc Mass of Ni56 ~ 1.2 1033 g Sound speed ~ 5 108cm/s Explosion Energy ~ 1051 ergs Explosion time ~ 1sec Velocity at infinity ~ 109 cm/s
CO
Relevant scales ~ 10-4 - 109 cm ~ 10-10 - 1s Re ~ 1015
Pr ~ 10-4
Le ~ 10-4
Degrees of freedom > 1040
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Most important observational fact: shell-like composition structure with high-velocity Si outside and low-velocity Fe inside.
1016 cm
1015 cm
Energy ~ 1018 ergs/g, or ~1051 ergs total
1014 cm
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deflagration (Sdef - parameter)
detonation
Carbon-Oxygen
Iron-group elements (56Ni,…)
Silicon-group elements(28Si,…)
DDT (transition density tr - parameter)
ignition
Delayed Detonation – Phenomenological Type Ia Model:
White Dwarf ignites, burns slowly and expands, then detonates.
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Nuclear Reactions in SNIa
FASTREACTIONS
SLOWREACTIONS
VERY VERY SLOWREACTIONS
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Hoeflich, 1995
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Direct determination of Ho: 1996
Ho = 68+-10 km/s/Mpc
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Deflagration Phase of Explosion
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Detonation Phase of Explosion
Confirms one-dimensional DD model. Qualitatively agrees with observations. Asymmetries predicted.
1010
Asymmetries observed
Lifan Wang et.al. 2006SN2004dt
1111
3D simulation in an expanding, non-inertial reference frame.
Alexei Poludnenko 2007.
From 1 sec to maximum light.
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Space of initial conditions
Space of observables 1,2,3
Space of absolute brightness
Physical correlations (theory)
Observed correlation
nearby
distant
Evolution effect, systematic error
Statistical error can be decreased by observing many SNIa. What can be done to eliminate systematic errors?
Theory need not be precise or complete. It must be good enough to describe large-scale correlation mechanisms in SNIa.
1313
Physical scales in SNIa
now
DDT