Precision ephemerides for gravitational-wave searches -- III. Revised system parameters of Sco X-1

Abstract

Neutron stars in low-mass X-ray binaries are considered promising candidate sources of continuous gravitational-waves. These neutron stars 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-LIGO 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 ${\mathrm{s}}^{-1}$, which we interpret as a revised upper limit to the projected orbital velocity of the NS $K_1$. By implementing Monte Carlo binary parameter calculations, and imposing new limits on $K_1$ and the rotational broadening, we obtained a complete set of dynamical system parameter constraints including a new range for $K_1$ of 40--90 km ${\mathrm{s}}^{-1}$. Finally, we discussed the implications of the updated orbital parameters for future continuous-waves searches.

11 pages, 7 figures. Accepted for publication in MNRAS

References in corpus (13)

• Detecting gravitational wave emission from the known accreting neutron stars
• Search for gravitational waves from Scorpius X-1 in the first Advanced LIGO observing run with a hidden Markov model
• Upper Limits on Gravitational Waves from Scorpius X-1 from a Model-Based Cross-Correlation Search in Advanced LIGO Data
• Detection of the Irradiated Donor in the LMXBs 4U 1636-536 (=V801 Ara) and 4U 1735-444 (=V926 Sco)
• Directed searches for continuous gravitational waves from binary systems: parameter-space metrics and optimal Scorpius X-1 sensitivity
• Gravitational waves from Sco X-1: A comparison of search methods and prospects for detection with advanced detectors
• Model-Based Cross-Correlation Search for Gravitational Waves from Scorpius X-1
• Dynamical constraints on the neutron star mass in EXO 0748-676
• System mass constraints for the accreting millisecond pulsar XTE J1814-338 using Bowen fluorescence
• Tuning into Scorpius X-1: adapting a continuous gravitational-wave search for a known binary system
• An Overview of the Bowen Survey; detecting donor star signatures in Low Mass X-ray Binaries
• Kinematical Studies of the Low Mass X-Ray Binary GR Mus (XB1254-690)
• Emission line tomography of the short period cataclysmic variables CC Scl and V2051 Oph

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