1. Core Collapse Supernovae: Power Beyond Imagination
Anthony Mezzacappa
Physical Science Directorate

2. Core collapse supernovae:
What are they?
- Explosions of massive stars
How often do they occur?
- About twice per century in our galaxy
Why are they important?
- The dominant source of elements in the Universe
Cas A Supernova Remnant
(Chandra Observatory)

3. Core collapse supernova paradigm

4. The most fundamental question in supernova theory
How is the supernova shock wave revived?
The most fundamental question in supernova theory
Gravity
Neutrino heating
Convection
Shock instability
Nuclear burning
Rotation
Magnetic fields
*New ingredient

5. Finding the recipe Neutrinos alone: No explosion Neutrinos Neutrinos
Convection
No explosion
Neutrinos
Convection
Nuclear burning
Explosion!
Neutrinos alone:
No explosion
Radius [km]
Liebendoerfer et al. (2001)
Bruenn et al. (2006)

6. Discovery through computing:
Stationary accretion shock instability (SASI)
The supernova shock wave is unstable!
l = 1 instability
Blondin, Mezzacappa, and DeMarino (2003)
SASI will aid the explosion and define the explosion’s shape (asphericity)

7. 2-dimensional vs 3-dimensional: The SASI case study

8. Blondin and Mezzacappa (2006)
Anatomy of a Mach reflection
Mach
Reflection
Blondin and Mezzacappa (2006)
Symmetry of Mach reflection broken in three dimensions
Internal shock (orthogonal to supernova shock) leads to two counter-rotating flows

9. SASI-induced rotational flow
Discovery through computing:
Generating pulsar spin in supernovae
SASI-induced rotational flow
Blondin and Mezzacappa (2006)
Deduced pulsar spin period from deposited angular momentum: 50 ms
Consistent with pulsar observations

10. Enabling supernova simulations
Solvers
Physics-based preconditioners
Newton-Krylov solvers
Management of large data sets
Parallel I/O
Networking
- Efficient (raw and/or derived) data access
- Protocols/provisioning on shared/dedicated links
Workflow integration/management/automation
Visualization
New representations
- Multidimensional (>3-dimensional) data
Efficient rendering of large data
- Hardware/software solutions
Interactivity
Remote visualization
Adaptive mesh refinement

11. The most fundamental questions remain
How do core collapse supernovae occur?
Are they powered largely by neutrinos, magnetic
fields, or both?
The bar is high: 3-dimensional simulation is required
Recent simulations have uncovered a new ingredient in supernova theory
Much remains to be done to include all model components in three dimensions
- Discovery through computation is alive and well
But we live in extraordinary times…
We can address this computational grand challenge
in all of its complexity for the very first time

12. Contacts Anthony Mezzacappa Physical Science Directorate
(865)
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