Measuring parameters of massive black hole binaries with partially aligned spins

摘要: The future space-based gravitational wave detector LISA will be able to measure parameters of coalescing massive black hole binaries, often extremely high accuracy. Previous work has demonstrated that the spins can have a strong impact on accuracy parameter measurement. Relativistic spin-induced precession modulates waveform in manner which break degeneracies between parameters, principle significantly improving how well they are measured. Recent studies indicated, however, spin may weak for an important subset astrophysical binary holes: those aligned due interactions with gas. In this paper, we examine binary's measured when its partially and compare results using waveforms include higher post-Newtonian harmonics truncated at leading quadrupole order. We find weakened substantially degrade estimation. This degradation is particularly devastating extrinsic sky position distance. Absent harmonics, typically localizes nearly factor $\ensuremath{\sim}6$ less accurately than one orientations random. Our knowledge source's thus worst gas-rich systems most likely produce electromagnetic counterparts. Fortunately, make up degradation. By including beyond our model, improved. some cases, as binaries