非表示:
キーワード:
General Relativity and Quantum Cosmology, gr-qc,Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO, Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE
要旨:
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 $1.4\,
M_\odot$ neutron star into a $10\,M_\odot$ black hole to a maximum distance of
$\sim 900$ Mpc. Achieving this sensitivity and extracting the physics imprinted
in observed signals requires accurate modeling of the binary to construct
template waveforms. In a NSBH 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 post-Newtonian (PN)
templates to model the gravitational waves emitted during the inspiral phase of
NSBH binaries. We restrict the black hole's spin to be aligned with the orbital
angular momentum and compare several approximants. We examine restricted
amplitude waveforms that are accurate to 3.5PN order in the orbital dynamics
and complete to 2.5PN order in the spin dynamics. We also consider PN waveforms
with the recently derived 3.5PN spin-orbit and 3PN spin-orbit tail corrections.
We compare these approximants to the effective-one-body model. For all these
models, large disagreements start at low to moderate black hole spins,
particularly for binaries where the spin is anti-aligned with the orbital
angular momentum. We show that this divergence begins in the early inspiral at
$v \sim 0.2$ for $\chi_{BH} \sim 0.4$. PN spin corrections beyond those
currently known will be required for optimal detection searches and to measure
the parameters of neutron star--black hole binaries. While this complicates
searches, the strong dependence of the gravitational-wave signal on the spin
dynamics will make it possible to extract significant astrophysical
information.
