Transcript Vacuum BH Studies AEI, Meudon, Palma, UPHEC Organization

Vacuum BH Studies
AEI, Meudon, Palma, UPHEC
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Organization
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All evolutions, most data sets generated in Cactus
AEI carries out most evolutions, Palma collaboration
Meudon generating better BBH initial data, in CVS,
Cactus
Techniques, codes transferred to other projects (e.g.
NS-NS, …)
UPHEC developing nonlinear perturbation studies
Ed Seidel
Albert Einstein Institute
www.eu-network.org
Sources of Gravitational Radiation
Colliding BH Roadmap:
A patchwork to success
Merger Phase
Post Newt
inspiral
Final Plunge
Time Scale
Technique
Post-Newtonian
t ~ 500+ M
t ~ 100 M
Need Post-N
gap
BH Initial data
Standard Numeical
relativity:
Exciting new results, get
farther and farther…
Ringdown
Time
Ed Seidel
Albert Einstein Institute
t ~ 30 M
Perturbative
www.eu-network.org
Sources of Gravitational Radiation
Distorted rotating BH's
modeling the late stages of BH coalescence,
perturbative comparisons
Uses excision,
New gauges,
Forms basis
for what
comes next…
Remarkable agreement between 2D and 3D!
Crash!
2D runs crashes!
Ed Seidel
Albert Einstein Institute
www.eu-network.org
Sources of Gravitational Radiation
3D BH Work
• Grazing Collision just
published in PRL last
month
• New formulations of EE’s
made it possible, but
• no shift
• no excision
• no co-rotation
Ed Seidel
Albert Einstein Institute
www.eu-network.org
Sources of Gravitational Radiation
“ISCO” series Initial Data
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Baumgarte studied initial data
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Now almost able to do orbits
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Equal mass, nonspinning BHs
Computer distance, momentum parameters for circular orbits
Estimated Innermost Stable Circular Orbit (ISCO)
Other circular orbits, too (“Pre-ISCO sequence: PI-1-10)
Here concentrate on PI-3
Not yet, but probably can, and probably not needed!
Problem: data sets so far coalesce before orbit! But code fine!
This is extraordinary
Many of same techniques apply directly to binary NS, binary
strange stars, etc.
Ed Seidel
Albert Einstein Institute
www.eu-network.org
Sources of Gravitational Radiation
Quantitative Analysis
Apparent Horizon Mass
M
l=m=2 Zerilli Waveform
Y
Time (M)
Ed Seidel
Albert Einstein Institute
Merger at t = 25M
Time (M)
www.eu-network.org
Sources of Gravitational Radiation
Meudon Binary BH Initial Data
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OP Group has generated
most astrophysically
relevant binary BH data to
date
How good? Recent Post-N
work at Paris indicates it is
very good!
These data sets already
imported into Cactus due to
Network activities
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Same interface as their
binary NS data, also in
Cactus!
Ed Seidel
Albert Einstein Institute
www.eu-network.org
Sources of Gravitational Radiation
Conclusions
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I have waited many years to see such results
 1D broke through barrier in 1987
 2D in 1993-5
 3D got stuck until last year…
Why is all this happening now?
 We have a great team! (Critical mass, talent, focus, coll)
 Developed much better theoretical
understanding/practical experience.
 We developed great collaborative technology
3+1 codes have smashed through the t = 30M barrier
 Shift to cure grid-stretching, co-rotation
 Orbits seems possible, but may not be necessary…
All this applies to NS-NS and other problems!
Ed Seidel
Albert Einstein Institute
www.eu-network.org
Sources of Gravitational Radiation