1. Modeling Type Ia Supernovae from ignition, to explosion, to emission
Daniel Kasen
UC Santa Cruz

2. Supernova Discovery History Asiago Catalog (all supernova types)

3. Supernova Discovery Future Rough predictions and promises…
Supernova Factory
Lick observatory SN search
CfA SN group
Carnegie SN project
ESSENCE
Supernova Legacy Survey
Can we use Type Ia SNe as reliable standard candles at the few % level?
Systematic error, not statistical error,
is the issue (e.g., luminosity evolution)
PanStarrs
Dark Energy Survey
JDEM
Large Synoptic Survey
Telescope (LSST)

4. SN Ia Progenitors Accreting white dwarf near the Chandrasekhar limit
Issues with the single degenerate scenario
Where is the hydrogen?
How do you make them in old (~10 Gyr) systems?
What about observed “Super-Chandra” events?
Could double white dwarf systems be the answer?
Accretion rate:
10-7 Msun / year

5. Fe
56Ni
Si/S/Ca
C/O
C/O
boom

6. Type Ia Supernova Light Curves powered by the beta decay: 56Ni 56Co 56Fe

7. Type Ia Width-Luminosity Relation brighter supernovae have broader light curves

8. Type Ia Supernova Spectrum
20 days after explosion

9. Toy Type Ia Supernova ModelsFe
56Ni
Si/S/Ca
C/O
Toy Type Ia Supernova Models
w/ Stan Woosley
Sergei Blinikov
Elena Sorokina
Spherical
Chandrasekhar mass
models with
varied composition
Parameters
MFe
MNi
MSi
“mixing”
MFe + MNi + MSi + Mco = MCH

10. 3-dimensional Time-Dependent Monte Carlo Radiative Transfer
SEDONA Code
Expanding atmosphere
Realistic opacities
Three-dimensional
Time-dependent
Multi-wavelength
Includes spectropolarization
Treats radioactive decay
and gamma-ray transfer
Iterative solution for
thermal equilibrium
Non-LTE capability
Kasen et al 2006 ApJ

11. EJECTA
MODEL

12. Broadband Synthetic Light Curves Model Compared to observations of SN 2001el
Parameters
MFe = 0.1 Msun
MNi = 0.6 Msun
MSi = 0.4 Msun
Kasen, ApJ 2006
Kasen (2006) ApJ

13. Time Evolution of Spectrum Recession of photosphere reveals deeper layers
Day 15 after explosion
Day 35 after explosion
C/O
Si/S/Ca
Model
SN1994D
56Ni Fe

14. Spectroscopic Time Series
Optical
Spectroscopic Time Series
Day 1 to Day 100

15. Width-Luminosity Relationship Kasen and Woosley, ApJ, 2007

16. Supernova Ejecta Opacity blending of millions of line transitions
FeII bound-bound
FeIII bound-bound

17. Infrared Secondary Maximum marks the transition from FeIII to FeII
I-Band
Kasen (2006) ApJ
All iron is FeII
T ~ 7000 K
FeIII starts becoming FeII

18. Infrared Secondary Maximum brighter supernovae have later secondary maxima
I-Band
Kasen (2006) ApJ
Vary 56Ni mass
from Msun
Kasen (2007)

19. Origin of the Width-Luminosity Relation dimmer SN are cooler, and recombine to FeII faster
B-band
I-band

20. Model Width-Luminosity Relation Woosley, Kasen, Blinnikov, Sorokina, ApJ (2007)
SN 99by
B-band
SN 91T

21. Presupernova Evolution Type Ia supernova modeling challenge
(~ years)
accreting, convective white dwarf
Type Ia
supernova
modeling
challenge
ignition
Explosion
(~1-100 secs)
turbulent nuclear combustion / hydrodynamics
free expansion
Light Curves / Spectra
(~1-100 days)
radioactive decay / radiative transfer
Observations

22. White Dwarf Convection and Ignition Kuhlen, Woosley, and Glaitzmeier (2006)

23. White Dwarf Convection (No rotation) 3-D calculation, Ma and Woosley

24. White Dwarf Convection (With Rotation) 3-D calculation, Ma and Woosley

25. 3D Deflagration Model Subsonic turbulent combustion
t = 1.5 sec
t = 1.0 sec
t = 0.0 sec
t = 0.5 sec
Roepke et al. (2005)

26. 2D Deflagration Model Roepke, Kasen, Woosley MNi = 0.2 Msun
EK = 0.3 x 1051 ergs

27. Gamezo et al.
Deflagration To Detonation Khokhlov (1991) Hoeflich (1994) Gamezo et al (2005)
But how to detonate?

28. 2D Delayed Detonation The stronger the deflagration phase
Roepke, Kasen, Woosley
The stronger the deflagration phase
 the more pre-expansion
 the lower the densities at detonation
 the less 56Ni produced
MNi = 0.5 Msun
EK = 1.2 x 1051 ergs

29. Off-Center Ignition
University of Chicago
FLASH Center

30. Hillebrandt, Sim, Roepke 2007
Off-center Detonation
Roepke, Kasen, Woosley
An alternative to
super-chandra SNe?
Howell et al, 2006
Hillebrandt, Sim, Roepke 2007
MNi = 1.0 Msun
EK = 1.3 x 1051 ergs

31. Spectrum of Off-center Detonation expansion velocities depend on orientation
I-Band
Kasen (2006) ApJ

32. Spectroscopic Homogeneity and Diversity monitoring silicon expansion velocities
from Leonard et al, ApJ 2006

33. Asymmetry and Polarization Observed SNeIa are polarized at ~0
Asymmetry and Polarization Observed SNeIa are polarized at ~0.4 % level

34. Asymmetry and Polarization Model polarization spectrum at maximum light as seen from different viewing angles

35. The Theoretical Understanding of Type Ia Supernovae
Pressing Questions
What are the progenitors?
How and where does ignition happen?
How might the deflagration transition into a
detonation?
How do the light curves depend upon the
progenitor and its environment?