B. P. Abbott, California Institute of Technology
R. Abbott, California Institute of Technology
T. D. Abbott, Louisiana State University
F. Acernese, Università degli Studi di Salerno
K. Ackley, University of Florida
C. Adams, LIGO Livingston
T. Adams, Université Savoie Mont Blanc
P. Addesso, Università degli Studi del Sannio
R. X. Adhikari, California Institute of Technology
V. B. Adya, Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
C. Affeldt, Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
M. Afrough, University of Mississippi
B. Agarwal, University of Illinois Urbana-Champaign
K. Agatsuma, FOM-Institute of Subatomic Physics - NIKHEF
N. Aggarwal, LIGO, Massachusetts Institute of Technology
O. D. Aguiar, Instituto Nacional de Pesquisas Espaciais
L. Aiello, Gran Sasso Science Institute
A. Ain, Inter-University Centre for Astronomy and Astrophysics India
P. Ajith, Tata Institute of Fundamental Research, Mumbai
B. Allen, Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
G. Allen, University of Illinois Urbana-Champaign
A. Allocca, Università di Pisa
H. Almoubayyed, University of Glasgow
P. A. Altin, The Australian National University
A. Amato, IN2P3 Institut National de Physique Nucleaire et de Physique des Particules
A. Ananyeva, California Institute of Technology
S. B. Anderson, California Institute of Technology
W. G. Anderson, University of Wisconsin-Milwaukee
S. Antier, Laboratoire de l'Accélérateur Linéaire
S. Appert, California Institute of Technology
K. Arai, California Institute of Technology
M. C. Araya, California Institute of Technology
J. S. Areeda, California State University, Fullerton

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Results are presented from a semicoherent search for continuous gravitational waves from the brightest low-mass X-ray binary, Scorpius X-1, using data collected during the first Advanced LIGO observing run. The search combines a frequency domain matched filter (Bessel-weighted F-statistic) with a hidden Markov model to track wandering of the neutron star spin frequency. No evidence of gravitational waves is found in the frequency range 60-650 Hz. Frequentist 95% confidence strain upper limits, h095%=4.0×10-25, 8.3×10-25, and 3.0×10-25 for electromagnetically restricted source orientation, unknown polarization, and circular polarization, respectively, are reported at 106 Hz. They are ≤10 times higher than the theoretical torque-balance limit at 106 Hz.

Publication Source (Journal or Book title)

Physical Review D