Core Oscillations and Instabilities in CoreCollapse Supernovae

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Core Oscillations and Instabilities in
Core-Collapse Supernovae
by Jeremiah Murphy (University of Arizona) in
collaboration with Adam Burrows, Ivan Hubeny, Luc
Dessart, Christian Ott, and Eli Livne
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Explosion Mechanism?
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Core Collapse Confirmed
Fe Core
IMB
1.4 M ?, R 3000 km
Tdyn 150 ms
Kamiokande
R 40 km
PNS
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The neutrino-mechanism
1D Fails
PNS (r 40 km)
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A New Asymmetric Instability

• Within the last 4 years
• SASI (Standing Accretion
• Shock Instability)
• P 35ms
• Blondin et al. 2003 and
• universally observed
• See Foglizzos Talk
• Significant departure from
• spherical symmetry
• Explosions? not robust

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One New Feature
Burrows, Livne, Dessart, Ott, Murphy 2006 ApJ,
640, 878
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A NewMechanism!
Robust

• Aspherical accretion
• excites core g-modes (P 3ms)
• Acoustic coupling
• Acoustic power 100
• absorbed behind shock
• Wait (0.5 - 1 s)
• aspherical explosion

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RemarkableBut!

• Confirmation of New Mechanism?
• Does the neutrino mechanism truly fizzle?
• g-modes exist, but to what extent are they
  excited?
• Role of acoustic and neutrino power?

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New Code Shopping List

• Multi-D Radiation Transport
• Multi-D Hydrodynamics
• Poissons equation for gravity
• General EOS
• New Accurate Techniques?
• All on Arbitrary-Unstructured Mesh

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Arbitrary Grids

• Nothing New
• Powerful technique

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What is New

• A New Algorithm for 2-D Transport for
  Astrophysical Simulations
• Hubeny Burrows, 2006
• Multi-D Hydrodynamics Arbitrary
  Lagrangian-Eulerian (ALE)
• Poissons equation for gravity
• Accurate
• Support-Operator Method - Shashkov (LANL)
• General EOS
• All on Arbitrary-Unstructured Mesh

BETHE Basic (2-Dimensional), Explicit/Implicit,
Transport and Hydronamics Explosion (Code)
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Unstructured Mesh A Powerfuland Widely
Applicable Tool
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Concluding Remarks

• Is the Acoustic Mechanism Relevant?
• BETHE Radiation-Hydrodynamics on
• Arbitrary Unstructured Grids
• Application for Other Astrophysical Phenomena