Document Type
Article
Publication Date
3-26-2015
Journal / Book Title
Physical Review D
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.
DOI
10.1103/PhysRevD.91.062008
MSU Digital Commons Citation
Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Favata, Marc; Ghosh, Shaon; and Martin, Rodica, "Directed Search for Gravitational Waves from Scorpius X-1 with Initial LIGO Data" (2015). Department of Physics and Astronomy Faculty Scholarship and Creative Works. 35.
https://digitalcommons.montclair.edu/physics-astron-facpubs/35
Published Citation
Aasi, J., Abbott, B. P., Abbott, R., Abbott, T., Abernathy, M. R., Acernese, F., ... & Cho, M. (2015). Directed search for gravitational waves from Scorpius X-1 with initial LIGO data. Physical Review D, 91(6), 062008.