First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

• Published in: arXiv.org 2017-12
• Main Authors: Agarwal, B, Agathos, M, Angelova, S V, Araya, M C, Aufmuth, P, AultONeal, K, Bazzan, M, Bondu, F, Bouffanais, Y, Calloni, E, Canizares, P, Cao, J, Cerretani, G, H -P Cheng, Chiummo, A, Chua, S, Chung, A K W, Ciani, G, Cirone, A, Cooper, S J, Coughlin, S B, Cunningham, L, D'alya, G, Day, B, S De, De Rosa, R, De Rossi, C, Edo, T B, Farinon, S, Fiori, I, Fishbach, M, Frasca, S, Freise, A, Garcia-Quiros, C, Gergely, L, Ghosh, Abhirup, Granata, M, Green, A C, Grote, H, Gruning, P, Hammond, G, Hannuksela, O A, Hild, S, Holz, D E, Husa, S, Indik, N, Jacqmin, T, Katsavounidis, E, Y -M Kim, Kleybolte, L, Koehlenbeck, S M, Korobko, M, Krishnan, B, Kuehn, G, Lang, R N, Li, T G F, Lynch, R, Magee, R M, Man, N, Mansell, G L, Mantovani, M, McCarthy, R, Mitrofanov, V P, Mitselmakher, G, Moore, C J, Nardecchia, I, Owen, B J, Page, M A, Phelps, M, Pierro, V, Pillant, G, Pinard, L, Prestegard, T, Quetschke, V, Read, J, Rocchi, A, Ross, M P, Schale, P, Shahriar, M S, Shaner, M B, Sieniawska, M, Sorrentino, F, Stops, D J, Strigin, S E, Summerscales, T Z, Sunil, S, Swinkels, B L, Tait, S C, Thomas, M, Trozzo, L, Valdes, G, N van Bakel, Veitch, P J, Walet, R, Walker, M, Ward, R L, Yamamoto, H, Zhang, L, Zhang, M, Zucker, M E
• Format: Article
• Language: English
• Subjects: Filtration; Gravitation; Gravitational waves; Neutron stars; Outliers (statistics); Parameters; Pulsars; Searching
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1710.02327

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, {\it narrow-band} analyses methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of eleven pulsars using data from Advanced LIGO's first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched: in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far.