Approaching the Post-Newtonian Regime with Numerical Relativity: A Compact-Object Binary Simulation Spanning 350...

Area of Science:

• Astrophysics
• Gravitational Wave Astronomy
• Numerical Relativity

Background:

• Accurate gravitational waveforms are essential for detecting and analyzing compact-object binaries.
• Current numerical-relativity simulations often lack the duration to cover the full frequency band of advanced detectors.

Purpose of the Study:

• To perform the first numerical-relativity simulation of a compact-object binary producing a gravitational waveform covering the entire frequency band of advanced detectors.
• To assess the accuracy of various waveform models against this comprehensive simulation.

Main Methods:

• Conducted a numerical-relativity simulation of a compact-object binary with a mass ratio of 7 and a total mass as low as 45.5 solar masses.
• Generated a gravitational waveform long enough to span the full frequency range of detectors like LIGO, Virgo, and KAGRA.

Main Results:

• Effective-one-body (EOB) models, even uncalibrated or calibrated on shorter waveforms, accurately reproduce the simulated waveform.
• A negligible loss in detection rate was observed due to modeling errors with EOB models.
• Post-Newtonian (PN) inspiral waveforms and phenomenological inspiral-merger-ringdown waveforms showed greater disagreement with the simulation.

Conclusions:

• Effective-one-body models demonstrate high fidelity for analyzing gravitational waves from compact-object binaries across the full detector frequency band.
• The accuracy of EOB models suggests they are robust for gravitational-wave data analysis, minimizing impact on detection rates.
• Discrepancies in PN and phenomenological models highlight the need for improved waveform generation techniques for certain binary configurations.