Tracking the precession of compact binaries from their gravitational-wave signal
- Author(s)
- Patricia Schmidt, Mark Hannam, Sascha Husa, Parameswaran Ajith
- Abstract
We present a simple method to track the precession of a black-hole-binary system during the inspiral, using only information from the gravitational-wave (GW) signal. Our method consists of locating the frame from which the magnitudes of the (l = 2, vertical bar m vertical bar = 2) modes are maximized, which we denote the "quadrupole-aligned" frame. We demonstrate the efficacy of this method when applied to waveforms from numerical simulations. In the test case of an equal-mass nonspinning binary, our method locates the direction of the orbital angular momentum to within (Delta theta, Delta phi) = (0.05 degrees, 0.2 degrees). We then apply the method to a q = M(2)/M(1) = 3 binary that exhibits significant precession. In general, a spinning binary's orbital angular momentum L is not orthogonal to the orbital plane. Evidence that our method locates the direction of L rather than the normal of the orbital plane is provided by comparison with post-Newtonian results. Also, we observe that it accurately reproduces similar higher-mode amplitudes to a comparable non-precessing binary, and that the frequency of the (l = 2, vertical bar m vertical bar = 2) modes is consistent with the "total frequency" of the binary's motion. The simple form of the quadrupole-aligned waveform may be useful in attempts to analytically model the inspiral-merger-ringdown signal of precessing binaries, and in standardizing the representation of waveforms for studies of accuracy and consistency of source modelling efforts, both numerical and analytical.
- Organisation(s)
- Gravitational Physics
- External organisation(s)
- University of the Balearic Islands, California Institute of Technology (Caltech)
- Journal
- Physical Review D
- Volume
- 84
- No. of pages
- 12
- ISSN
- 1550-7998
- DOI
- https://doi.org/10.1103/PhysRevD.84.024046
- Publication date
- 2011
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103036 Theoretical physics, 103004 Astrophysics, 103028 Theory of relativity, 102023 Supercomputing
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/a3acf22d-9e48-4840-86f6-3256f94708aa