1 / 30

Exploding Massive Stars:

Exploding Massive Stars:. The Perfect ‘App’ for Computational Physics. John M. Blondin. North Carolina State University. SESAPS 2003. What is a supernova?. A single, new star outshines an entire galaxy for weeks. The High-Z Supernova Search. The High-Z Supernova Search.

pilis
Download Presentation

Exploding Massive Stars:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Exploding Massive Stars: The Perfect ‘App’ for ComputationalPhysics John M. Blondin North Carolina State University SESAPS 2003

  2. What is a supernova? A single, new star outshines an entire galaxy for weeks.

  3. The High-Z Supernova Search

  4. The High-Z Supernova Search

  5. The Crab Supernova Remnant This debris is located in the same position as a supernova seen by Chinese astronomers in 1054.

  6. Historical Supernovae Year Report Status 1006 China, Arab lands, Europe Identified with radio SNR 1054 China, Japan Crab Nebula 1181 China, Japan SNR 3C58 1572 Europe (Tycho Brahe), China Tycho's remnant 1604 Europe (Kepler), Japan, Korea Kepler's remnant

  7. CassiopeiaA Radio Optical X-Ray

  8. What are we looking at? • Brightness & distance => 10 billion Suns • Doppler shifts => expansion at 1000 km/s • X-Ray emission => few solar masses An expanding blastwave with 1051 ergs

  9. Where did all that energy come from? Type Ia - stellar-sized nuclear bomb Type II - gravitational collapse of a massive star

  10. SN1987A confirmed the basic supernova theory • A star disappeared! Supernovae do result from the death of a massive star. • Neutrinos were detected (2002 Nobel Prize), confirming formation of neutron star in the core.

  11. What is left to learn? • How do they explode?! • What is the neutrino signature? • Do they produce gravitational waves?

  12. A Brief History of Supernova Theory Thermonuclear runaway in envelope Neutrino-Driven prompt explosion Shock reheating via neutrino energy deposition Convective instability above neutrino-sphere • 1957 Burbidge, Burbidge, Fowler, and Hoyle • 1966 Colgate and White • 1985 Bethe and Wilson • 1992 Herant, Benz, and Colgate

  13. Anatomy of a Supernova Need Boltzmann Solution • Need Angular Distribution • Need Spectrum • Need Neutrino Distribution • Fluid Instabilities • Rotation • Magnetic Fields Need these to few percent accuracy! 6D RMHD Problem!

  14. TeraScale Supernova Initiative http://www.phy.ornl.gov/tsi/ Explosions of Massive Stars • Relevance: • Element Production • Cosmic Laboratories • Driving Application • 10 Institution, 17 Investigator, ~ 40 Person, Interdisciplinary Effort • ascertain the core collapse supernova mechanism(s) • understand supernova phenomenology • e.g.: (1) element synthesis, (2) neutrino, gravitational wave, and gamma ray signatures • provide theoretical foundation in support of OS experimental facilities (RHIC, SNO, RIA, NUSL) • develop enabling technologies of relevance to many applications • e.g. 3D, multifrequency, precision radiation transport • serve as testbed for development and integration of technologies in simulation “pipeline” • e.g. data management, networking, data analysis, and visualization With ISIC and other collaborators: ~120 people from 24 institutions involved.

  15. What will it take? • Tera/Peta-Scale 3D, General Relativistic, Radiation Magnetohydrodynamics • State of the Art Nuclear and Weak Interaction Physics • “Infrastructure” Needs: Applied Mathematics • Tera- and Peta-Scale Sparse Linear Systems of Equations • “Infrastructure” Needs: Data Management/Visualization • 1-10 Tb/Variable/Simulation! • Manage? • Analyze? • Render? • “Infrastructure” Needs: Networking • How can a nationally distributed team work together effectively?

  16. Completed: Spherical Models with Boltzmann Transport Newtonian General Relativistic Messer et al. (2002) Liebendoerfer et al. (2002) • No Explosions! • New Microphysics? • High-Density Stellar Core Thermodynamics • Neutrino-Matter Interactions • New Macrophysics? (2D/3D Models) • Fluid Instabilities, Rotation, Magnetic Fields TSI will explore both! • No 2D/3D supernova models with realistic neutrino transport exist!

  17. One Dimension is Too Simple

  18. SAS Solution is Stable in One Dimension Pressure perturbation radius time

  19. SASI: l=1 mode is overstable Shock normal Spherical shock Radial in-fall The obliquity of the accretion shock deflects the radial in-flow

  20. SASI

  21. Challenges in Data Management

  22. First steps toward understanding the role of magnetic fields… • What impact will they have on the collapse and postbounce dynamics? • How much do they factor into generating the explosion? • How much will they be amplified, and how? • Wrapping • Dynamo • Magnetorotational Instability (Balbus and Hawley 1991) • Akiyama et al. (2002) SASI + Dipole Field Asif ud-Doula (see poster)

  23. How did this happen?!

More Related