Bibcode
Marsh, T.; Casares, J.; Galloway, D. K.; Wang, L.; Steeghs, D.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 478, Issue 4, p.5174-5183
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8
2018
Citations
21
Refereed citations
21
Description
Neutron stars (NSs) in low-mass X-ray binaries are considered promising
candidate sources of continuous gravitational waves. These NSs are
typically rotating many hundreds of times a second. The process of
accretion can potentially generate and support non-axisymmetric
distortions to the compact object, resulting in persistent emission of
gravitational waves. We present a study of existing optical
spectroscopic data for Sco X-1, a prime target for continuous
gravitational-wave searches, with the aim of providing revised
constraints on key orbital parameters required for a directed search
with advanced Laser Interferometer Gravitational-Wave Observatory data.
From a circular orbit fit to an improved radial velocity curve of the
Bowen emission components, we derived an updated orbital period and
ephemeris. Centre of symmetry measurements from the Bowen Doppler
tomogram yield a centre of the disc component of 90 km s-1,
which we interpret as a revised upper limit to the projected orbital
velocity of the NS K1. By implementing Monte Carlo binary
parameter calculations, and imposing new limits on K1 and the
rotational broadening, we obtained a complete set of dynamical system
parameter constraints including a new range for K1 of 40-90
km s-1. Finally, we discussed the implications of the updated
orbital parameters for future continuous-wave searches.
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Black holes, neutron stars, white dwarfs and their local environment
Accreting black-holes and neutron stars in X-ray binaries provide an ideal laboratory for exploring the physics of compact objects, yielding not only confirmation of the existence of stellar mass black holes via dynamical mass measurements, but also the best opportunity for probing high-gravity environments and the physics of accretion; the most
Montserrat
Armas Padilla