Lazarus Approach to Binary Black Hole Modeling

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Lazarus Approach to Binary Black Hole Modeling

• Goddard Gravitational Wave Astrophysics
  Numerical Relativity Group
• Joan Centrella
• John Baker
• Dae-Il Choi
• Jim Van Meter
• David Fiske
• Breno Imbiriba
• David Brown (NCSU)

• Lazarus Group
• UTB CGWA
• Manuela Campanelli
• Carlos Lousto
• Mark Hannam
• Enrique Pazos
• Yosef Zlochower
• Goddard Space Flight Center
• John Baker
• Louisiana State University
• Ryoji Takahashi

Building Bridges CGWA Inauguration 15 December
2003

• John Baker
• Laboratory for High Energy Astrophysics
• NASA/Goddard Space Flight Center

Lazarus Group
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Modeling Binary Black Hole Coalescence
Far Limit Methods
LISA
Numerical Simulations
Terrestrial GW Detectors
Close Limit
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108x108 at z2
107x107 at z1
106x106 at z1
106x105.5 at z1
105x105 at z10
104x104 at z2
103x103 at z2
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Modeling Binary Black Hole Coalescence
Far Limit Methods
LISA
Numerical Simulations
Terrestrial GW Detectors
Close Limit
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Binary Black HoleSpacetime
time
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LazarusModel
Close Limit
Numerical Simulation
Far Limit
time
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Lazarus Model Results Equal mass non-spinning
black holes

• Rapid plunge
• Some support for simple far limit model
• Circular polarization pattern
• As for a rotating body
• Efficient angular momentum radiation (?J?/2 ?E)
• Instantaneous frequency
• 2.5 of system energy radiated post-ISCO
• Simple dynamical picture
• Analytic waveform fit...
• More physics
• Spins
• Unequal masses

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Lazarus Model Results Equal mass non-spinning
black holes

• Rapid plunge
• Some support for simple far limit model
• Circular polarization pattern
• As for a rotating body
• Efficient angular momentum radiation (?J?/2 ?E)
• Instantaneous frequency
• 2.5 of system energy radiated post-ISCO
• Simple dynamical picture
• Analytic waveform fit...
• More physics
• Spins
• Unequal masses

Spins
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Lazarus Model Results Equal mass
spinning black holes

• Simple waveforms
• Like non-spinning case
• Also seen in PN studies
• Similar after rescaling by ?QN
• Circular polarization pattern
• Post-ISCO Energy 2-2.5
• Angular momentum final BH a/m?
• Roughly half the added angular momentum
  retained
• Seems difficult to form a maximally rotating BH
• Whats next?
• Unequal masses
• improvements

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Improved Model
time
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Improved Model

• Problems
• Limited accuracy
• Instability
• Outer boundaries
• Error grows rapidly in time

• LazEv
• Higher order finite differencing
• Better coordinate gauge choice
• ADM/BSSN systems
• New (Cactus) evolution code LazEv
• Mathematica based coding
• Allows greater complexity
• Adaptable

time
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Improved Model

• Problems
• Limited accuracy
• Instability
• Outer boundaries
• Error grows rapidly in time

• Goddard Approach
• Fixed/Adaptive Refinement
• Better coordinate gauge choice
• BSSN system
• Collaboration with CGWA on
• Lazarus model application

time
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Improved Model
Application Coming 2004
time
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• Applications
• Refinement of previous results with greater
  sensitivity
• Initial data transients
• Waveform spin dependence
• Higher-order multipole radiation components
• Enlarged applicable problem space
• Increased range of mass ratios (kicks)
• Increased initial separations
• Emerging technology
• Improved NS-CL interface (with C. Beetle,Y. Mino)
• Greater application of post-Newtonian techniques
• Initial data varieties
• Further advances in Numerical Sims.

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End