Accuracy of gravitational waveform models for observing neutron-star–black-hole binaries in Advanced LIGO

Gravitational waves radiated by the coalescence of compact-object binaries containing a neutron star and a black hole are one of the most interesting sources for the ground-based gravitational-wave observatories Advanced LIGO and Advanced Virgo. Advanced LIGO will be sensitive to the inspiral of a 1.4M neutron star into a 10M black hole to a maximum distance of ~900 Mpc. Achieving this sensitivity and extracting the physics imprinted in observed signals requires accurate modeling of the binary to construct template waveforms. In a neutron-star-black-hole binary, the black hole may have significant angular momentum (spin), which affects the phase evolution of the emitted gravitational waves. We investigate the ability of currently available post-Newtonian templates to model the gravitational waves emitted during the inspiral phase of neutron-star-black-hole binaries. Post-Newtonian spin corrections beyond those currently known will be required for optimal detection searches and to measure the parameters of neutron-star-black-hole binaries. The strong dependence of the gravitational-wave signal on the spin dynamics will make it possible to extract significant astrophysical information from detected systems with Advanced LIGO and Advanced Virgo.