1. 1 1 Physics of Type Ia Supernova Explosions A. Khokhlov, A.Poludnenko (The University of Chicago) Lifan Wang (A&M) P. Hoeflich (U Florida)

2. 2 2 Carbon-Oxygen White Dwarf Exploding as a SNIa. R=2.10 8 cm Mass ~ 2.8 10 33 g Temperatures ~ 3 – 9 10 9 K Density ~ 2.0 10 9 g/cc Mass of Ni 56 ~ 1.2 10 33 g Sound speed ~ 5 10 8 cm/s Explosion Energy ~ 10 51 ergs Explosion time ~ 1sec Velocity at infinity ~ 10 9 cm/s CO Relevant scales ~ 10 -4 - 10 9 cm ~ 10 -10 - 1s Re ~ 10 15 Pr ~ 10 -4 Le ~ 10 -4 Degrees of freedom > 10 40

3. 3 3 Most important observational fact: shell-like composition structure with high-velocity Si outside and low-velocity Fe inside. 10 16 cm 10 15 cm Energy ~ 10 18 ergs/g, or ~10 51 ergs total 10 14 cm

4. 4 4 deflagration (S def - parameter) detonation Carbon-Oxygen Iron-group elements ( 56 Ni,…) Silicon-group elements( 28 Si,…) DDT (transition density  tr - parameter) ignition Delayed Detonation – Phenomenological Type Ia Model: White Dwarf ignites, burns slowly and expands, then detonates.

5. 5 5 Nuclear Reactions in SNIa FAST REACTIONS SLOW REACTIONS VERY VERY SLOW REACTIONS

6. 6 6 Hoeflich, 1995

7. 7 7 Direct determination of H o : 1996 H o = 68+-10 km/s/Mpc

8. 8 8 Deflagration Phase of Explosion

9. 9 9 Detonation Phase of Explosion Confirms one-dimensional DD model. Qualitatively agrees with observations. Asymmetries predicted.

10. 10 Asymmetries observed Lifan Wang et.al. 2006 SN2004dt

11. 11 3D simulation in an expanding, non-inertial reference frame. Alexei Poludnenko 2007. From 1 sec to maximum light.

12. 12 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.

13. 13 Physical scales in SNIa now DDT