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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.

55

Nuclear Reactions in SNIa

FASTREACTIONS

SLOWREACTIONS

VERY VERY SLOWREACTIONS

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Hoeflich, 1995

77

Direct determination of Ho: 1996

Ho = 68+-10 km/s/Mpc

88

Deflagration Phase of Explosion

99

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.

1212

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