Detecting gravitational waves from precessing binaries of spinning compact objects: Adiabatic limit

Abstract

Black-hole (BH) binaries with single-BH masses $m=(5\mathrm{\ensuremath{-}}{20)M}_{\ensuremath{\bigodot}},$ moving on quasicircular orbits, are among the most promising sources for first-generation ground-based gravitational-wave (GW) detectors. Until now, the development of data-analysis techniques to detect GWs from these sources has been focused mostly on nonspinning BHs. The data-analysis problem for the spinning case is complicated by the necessity to model the precession-induced modulations of the GW signal, and by the large number of parameters needed to characterize the system, including the initial directions of the spins, and the position and orientation of the binary with respect to the GW detector. In this paper we consider binaries of maximally spinning BHs, and we work in the adiabatic-inspiral regime to build families of modulated detection templates that (i) are functions of very few physical and phenomenological parameters, (ii) model remarkably well the dynamical and precessional effects on the GW signal, with fitting factors on average $\ensuremath{\gtrsim}0.97,$ (iii) but, however, might require increasing the detection thresholds, offsetting at least partially the gains in the fitting factors. Our detection-template families are quite promising also for the case of neutron-star--black-hole binaries, with fitting factors on average $\ensuremath{\approx}0.93.$ For these binaries we also suggest (but do not test) a further template family, which would produce essentially exact waveforms written directly in terms of the physical spin parameters.