Measuring the spin of black holes in binary systems using gravitational waves

Vitale, S., Lynch, R., Veitch, J. , Raymond, V. and Sturani, R. (2014) Measuring the spin of black holes in binary systems using gravitational waves. Physical Review Letters, 112(251101), (doi: 10.1103/PhysRevLett.112.251101) (PMID:25014800)

Abstract

Compact binary coalescences are the most promising sources of gravitational waves (GWs) for ground-based detectors. Binary systems containing one or two spinning black holes are particularly interesting due to spin-orbit (and eventual spin-spin) interactions and the opportunity of measuring spins directly through GW observations. In this Letter, we analyze simulated signals emitted by spinning binaries with several values of masses, spins, orientations, and signal-to-noise ratios, as detected by an advanced LIGO-Virgo network. We find that for moderate or high signal-to-noise ratio the spin magnitudes can be estimated with errors of a few percent (5%–30%) for neutron star–black hole (black hole–black hole) systems. Spins’ tilt angle can be estimated with errors of 0.04 rad in the best cases, but typical values will be above 0.1 rad. Errors will be larger for signals barely above the threshold for detection. The difference in the azimuth angles of the spins, which may be used to check if spins are locked into resonant configurations, cannot be constrained. We observe that the best performances are obtained when the line of sight is perpendicular to the system’s total angular momentum and that a sudden change of behavior occurs when a system is observed from angles such that the plane of the orbit can be seen both from above and below during the time the signal is in band. This study suggests that direct measurement of black hole spin by means of GWs can be as precise as what can be obtained from x-ray binaries.

• Item Type: Articles
• Additional Information: S. V., R. L., and V. R. acknowledge the support of the National Science Foundation and the LIGO Laboratory. LIGO was constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the National Science Foundation and operates under cooperative agreement PHY-0757058. J.V. was supported by the research program of the Foundation for Fundamental Research on Matter (FOM), which is partially supported by the Netherlands Organisation for Scientific Research (NWO), and by STFC Grant No. ST/K005014/1. V. R. is supported by a Richard Chase Tolman fellowship at the California Institute of Technology. R. S. is supported by the FAPESP Grant No. 2013/04538-5. The authors would like to acknowledge the LIGO Data Grid clusters, without which the simulations could not have been performed. Specifically, these include the Syracuse University Gravitation and Relativity cluster, which is supported by NSF Grants No. PHY-1040231 and No. PHY-1104371.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Veitch, Dr John
• Authors: Vitale, S., Lynch, R., Veitch, J., Raymond, V., and Sturani, R.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review Letters
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114
• Published Online: 25 June 2014