A directed search for gravitational waves from Scorpius X-1 with initial LIGO

Document #:

LIGO-P1400094-v20

Document type:

P - Publications

Abstract:

We present results of a search for continuously-emitted gravitational radiation, directed at the brightest low-mass X-ray binary, Scorpius X-1. Our semi-coherent analysis covers 10 days of LIGO S5 data ranging from 50–550 Hz, and performs an incoherent sum of coherent F-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3 × 10−24 and 8 × 10−25 are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof of principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of ~1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector.

Files in Document:

• S5_SidebandSearch_ScoX1.pdf (1.1 MB)

Other Files:

• sideband_review_summary.pdf (35.1 kB)
• paper presentation (20141103_Sideband.pdf, 1.5 MB)

Topics:

• Continuous Wave

Author Groups:

• LSC

Keywords:

continuous wave Low-mass X-ray binaries Sco X-1

Related Documents:

Publication Information:

ArXiv: http://arxiv.org/abs/1412.0605
Science summary: http://www.ligo.org/science/Publication-S5SidebandScoX1/index.php