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arXiv · 1704.03719

Search for gravitational waves from Scorpius X-1 in the first Advanced LIGO observing run with a hidden Markov model

The LIGO Scientific Collaboration·the Virgo Collaboration·B. P. Abbott·R. Abbott·T. D. Abbott·F. Acernese·K. Ackley·C. Adams·T. Adams·P. Addesso·R. X. Adhikari·V. B. Adya·C. Affeldt·M. Afrough·B. Agarwal·K. Agatsuma·N. Aggarwal·O. D. Aguiar·L. Aiello·A. Ain·P. Ajith·B. Allen·G. Allen·A. Allocca·H. Almoubayyed·P. A. Altin·A. Amato·A. Ananyeva·S. B. Anderson·W. G. Anderson·S. Antier·S. Appert·K. Arai·M. C. Araya·J. S. Areeda·N. Arnaud·K. G. Arun·S. Ascenzi·G. Ashton·M. Ast·S. M. Aston·P. Astone·P. Aufmuth·C. Aulbert·K. AultONeal·A. Avila-Alvarez·S. Babak·P. Bacon·M. K. M. Bader·S. Bae·P. T. Baker·F. Baldaccini·G. Ballardin·S. W. Ballmer·S. Banagiri·J. C. Barayoga·S. E. Barclay·B. C. Barish·D. Barker·F. Barone·B. Barr·L. Barsotti·M. Barsuglia·D. Barta·J. Bartlett·I. Bartos·R. Bassiri·A. Basti·J. C. Batch·C. Baune·M. Bawaj·M. Bazzan·B. B'ecsy·C. Beer·M. Bejger·I. Belahcene·A. S. Bell·B. K. Berger·G. Bergmann·C. P. L. Berry·D. Bersanetti·A. Bertolini·Z. B. Etienne·J. Betzwieser·S. Bhagwat·R. Bhandare·I. A. Bilenko·G. Billingsley·C. R. Billman·J. Birch·R. Birney·O. Birnholtz·S. Biscans·A. Bisht·M. Bitossi·C. Biwer·M. A. Bizouard·J. K. Blackburn·J. Blackman·C. D. Blair
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Abstract

Results are presented from a semi-coherent 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 (O1). The search combines a frequency domain matched filter (Bessel-weighted $\mathcal{F}$-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, $h_0^{95\%} = 4.0\times10^{-25}$, $8.3\times10^{-25}$, and $3.0\times10^{-25}$ for electromagnetically restricted source orientation, unknown polarization, and circular polarization, respectively, are reported at 106 Hz. They are $\leq 10$ times higher than the theoretical torque-balance limit at 106 Hz.

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The LIGO Scientific Collaboration, the Virgo Collaboration, B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Afrough, B. Agarwal, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, A. Allocca, H. Almoubayyed, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, N. Arnaud, K. G. Arun, S. Ascenzi, G. Ashton, M. Ast, S. M. Aston, P. Astone, P. Aufmuth, C. Aulbert, K. AultONeal, A. Avila-Alvarez, S. Babak, P. Bacon, M. K. M. Bader, S. Bae, P. T. Baker, F. Baldaccini, G. Ballardin, S. W. Ballmer, S. Banagiri, J. C. Barayoga, S. E. Barclay, B. C. Barish, D. Barker, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, J. Bartlett, I. Bartos, R. Bassiri, A. Basti, J. C. Batch, C. Baune, M. Bawaj, M. Bazzan, B. B'ecsy, C. Beer, M. Bejger, I. Belahcene, A. S. Bell, B. K. Berger, G. Bergmann, C. P. L. Berry, D. Bersanetti, A. Bertolini, Z. B. Etienne, J. Betzwieser, S. Bhagwat, R. Bhandare, I. A. Bilenko, G. Billingsley, C. R. Billman, J. Birch, R. Birney, O. Birnholtz, S. Biscans, A. Bisht, M. Bitossi, C. Biwer, M. A. Bizouard, J. K. Blackburn, J. Blackman, C. D. Blair. 2017-04-12. Search for gravitational waves from Scorpius X-1 in the first Advanced LIGO observing run with a hidden Markov model. https://doi.org/10.1103/physrevd.95.122003

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