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EU Astrophysics Network Overview

LIGO-G020158-00-Z. EU Astrophysics Network Overview. Progress on 3D BH Collsions (me) 3D Hydro (Luciano) Stellar Instabilities (Nils). Ed Seidel Albert-Einstein-Institute Principal Network Coordinator. Computational Tools. Theoretical Tools. Einstein Eqs. Post-Newtonian Theory.

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EU Astrophysics Network Overview

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  1. LIGO-G020158-00-Z EU Astrophysics Network Overview • Progress on 3D BH Collsions (me) • 3D Hydro (Luciano) • Stellar Instabilities (Nils) Ed Seidel Albert-Einstein-Institute Principal Network Coordinator www.eu-network.org Sources of Gravitational Radiation

  2. Computational Tools Theoretical Tools Einstein Eqs Post-Newtonian Theory Cactus Viz Pert. theory Grid ASC Objectives of NetworkA Training program to build a community Enablers Focus Physics Areas Other (strange stars, Core collapse, etc) 3D NS processes and mergers 3D BH Collisions ZIB/Garching LBL/NCSA/ANL People 65:10! Outreach /Leverage Cactus Community World GridLab NSF ASC www.eu-network.org Sources of Gravitational Radiation

  3. BH Data/Evolutions Post-Newtonian Schemes Characteristic Codes Perturbative Time Evolutions Cactus Dev/Training Nonlinear GR Hydro And Applications Stellar Pert Theory Ports Potsdam Ports Ports Potsdam Potsdam SOTON CS Efforts Worldwide SOTON SOTON Jena Jena Jena Jena Meudon Meudon Trieste Trieste AUTH Rome AUTH AUTH Rome Rome Valencia Valencia Valencia Valencia Valencia Palma Palma Palma Palma Our Team7 Focus areas, links created, strengthened by Network Ports Potsdam SOTON Jena Jena Meudon WashU Trieste AUTH Rome Valencia Palma www.eu-network.org Sources of Gravitational Radiation

  4. Step 0: Better Formulations (BSSN), gauges, excision Step 1: Do 3D single, rotating distorted BHs individually t ~ 100s - 1000s M with convergence, solid masses, waveforms Some instability may appear after t ~ 200 - 500M in full 3D Step 2: Do head -on BH collisions 100s - 1000s M with convergence, solid masses, waveforms Step 3: Go to co-rotating frame for orbits! Can just about do this today… Steps to BBH Orbits(AEI/UT-Brownsville/Meudon) www.eu-network.org Sources of Gravitational Radiation

  5. Remarkable agreement between 2D and 3D! 2D run, no excision, no shift, high resolution Crash! Crash! 3D run, no excision, no shift Old 2D runs crash! Crash! 3D run, excision+shift Highly Distorted Rotating BH Waveform Step 1:Single 3D BHs Become “Routine” Comparison of Schwarzschild BHs www.eu-network.org Sources of Gravitational Radiation

  6. Brill-Lindquist Approx ISCO separation No momentum Similar to Misner m=2.2 New dynamic shift/lapse combo No Excision!!! Step 2: 3D Head-On Collisions “Routine” AH Mass 0 5000 Time (M) From Peter Diener… www.eu-network.org Sources of Gravitational Radiation

  7. Step 3: Co-rotating frame for Orbits • New Techniques • Excision • Gauges, formulations • Co-rotating frame • Baumgarte initial data • Estimated Innermost Stable Circular Orbit (ISCO) • Other circular orbits, too (“Pre-ISCO” sequence: PI-1-10) From Denis Pollney… www.eu-network.org Sources of Gravitational Radiation

  8. Baumgarte Orbital Period Estimate Run Lifetimes (Very early attempts) Coalescence time Overview of Evolutions So Far • Major problem is finding data sets that want to orbit! • Baumgarte data • Seem to have momentum too low for circular orbits • W seems to be overestimated by factor of 2 • Evolutions solid (e.g., horizon mass accurate to 10% at t~100M) Time (M) Pre-ISCO model www.eu-network.org Sources of Gravitational Radiation

  9. Example: Pre-ISCO 3 AHs andY4 (Corotation taken out) Kzz in x-y plane, showing excision (corotating) www.eu-network.org Sources of Gravitational Radiation

  10. Meudon Full GR Numerical BBH Initial Data Increasing sophistication in IVPGrandclement (Meudon) BBH data • Builds in approx helical Killing vector • Has orbital period of ~ 2x that of potential method (also what we see in evolutions!) • Post-Newtonian expansions seem to converge towards the numerical BBH data • Meudon Group: most astrophysically relevant binary BH data to date. Now in Cactus as EU Network Project (from Luc Blanchet) www.eu-network.org Sources of Gravitational Radiation

  11. GridLab: www.gridlab.orgEnabling Dynamic Grid Applications • EU Project (€5M) • AEI, ZIB, PSNC, Lecce, Athens, Cardiff, Amsterdam, SZTAKI, Brno, ISI, Argonne, Wisconsin, Sun, Compaq • Grid Application Toolkit for application developers (APIs/Tools) • Develop new grid scenarios for 2 main apps: • Numerical relativity • Grav wave data analysis www.eu-network.org Sources of Gravitational Radiation

  12. Discovery Channel wantsPre-ISCO 3! This June… www.eu-network.org Sources of Gravitational Radiation

  13. Building a Community (through) Code: Advantages • Sharing of Expertise: No single group or community can do these problems • Sharing of Code among projects • Infrastructure • BH routines apply directly to NS work, etc… • But free to keep routines in group as long as desired • Better Code • Open source encourages people to be more careful in coding! • Encourages documentation • Encourages deeper thinking about how it interfaces to another code • More trusted code, results • When code becomes open, and people can run it for themselves, they will begin to believe the results • Improvements propagate quickly though community • Not well accepted yet, but we are starting a good trend… www.eu-network.org Sources of Gravitational Radiation

  14. Cactus User CommunityUsing and Developing Physics Thorns Numerical Relativity/Astrophysics Other Applications UNAM AEI Soton Wash U RIKEN Chemical Engineering (U.Kansas) Goddard Pitt PSU Thessaloniki Monash Climate Modeling (NASA,AMS) Tuebingen TAC SISSA Portsmouth UT EU Astrophysics Network NASA Arizona Bio-Informatics (Canada) Etc… Geophysics (Stanford) Early Universe (LBL) Meeting in May: Theoretical Foundations of Einstein’s Equations for Numerical Relativity (Using Cactus to investigate and compare different implementations) Plasma (Princeton) Astrophysics (Zeus) www.eu-network.org Sources of Gravitational Radiation

  15. Grazing Collision 1999 Big Advance: 3D, unequal mass, spin, J Physics! But Code crash by 40M Previous 3D BH Resultsnew formulations, no shift, no excision www.eu-network.org Sources of Gravitational Radiation

  16. Horizon Mass for Pre-ISCO 4 • Low resolution (192x192x96), but mass conserved to ~ 10% until ~100M • Now exploring parameters to find orbital configurations www.eu-network.org Sources of Gravitational Radiation

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