Bibcode
Premachandra, S. S.; Galloway, D. K.; Casares, J.; Steeghs, D. T.; Marsh, T. R.
Bibliographical reference
The Astrophysical Journal, Volume 823, Issue 2, article id. 106, pp. (2016).
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6
2016
Journal
Citations
10
Refereed citations
10
Description
Accreting neutron stars in low-mass X-ray binaries are candidate
high-frequency persistent gravitational wave sources. These may be
detectable with next-generation interferometers such as Advanced
LIGO/VIRGO within this decade. However, the search sensitivity is
expected to be limited principally by the uncertainty in the binary
system parameters. We combine new optical spectroscopy of Cyg X-2
obtained with the Liverpool Telescope with available historical radial
velocity data, which gives us improved orbital parameter uncertainties
based on a 44 year baseline. We obtained an improvement of a factor of
2.6 in the orbital period precision and a factor of 2 in the epoch of
inferior conjunction T 0. The updated orbital parameters
imply a mass function of 0.65 ± 0.01 M ⊙, leading
to a primary mass (M 1) of 1.67 ± 0.22 M
⊙ (for i = 62.{}^\circ 5+/- 4^\circ ). In addition, we
estimate the likely orbital parameter precision through to the expected
Advanced LIGO and VIRGO detector observing period and quantify the
corresponding improvement in sensitivity via the required number of
templates.