Title:	Directed search for gravitational waves from Scorpius X-1 with initial LIGO data
Authors:	Aasi, J. Abbott, B.P. Abbott, R. Iyer, B.R. LIGO Scientific Collaboration and Virgo Collaboration +250 Co authors
Issue Date:	15-Mar-2015
Publisher:	American Physical Society
Citation:	Physical Review D, 2015, Vol.91, p 062008
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 semicoherent 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.
Description:	Open Access
URI:	http://hdl.handle.net/2289/6272
ISSN:	1550-7998 1550-2368(Online)
Alternative Location:	http://arxiv.org/abs/1412.0605 http://dx.doi.org/10.1103/PhysRevD.91.062008 http://adsabs.harvard.edu/abs/2015PhRvD..91f2008A
Copyright:	2015 American Physical Society
Appears in Collections:	Research Papers (TP)

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