All-sky LIGO Search for Periodic Gravitational Waves in the Early S5 Data
All-sky LIGO Search for Periodic Gravitational Waves in the Early S5 Data
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全天 LIGO 搜索早期 S5 数据中的周期性引力波
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
L. S. Collaboration
中科院分区：
文献类型：
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作者：
L. S. Collaboration
我们报道了用LIGO探测器全天搜索频率在50 - 1100 Hz，频率时间导数在- 5 × 10 - 9 - 0 Hz s - 1范围内的周期性引力波。LIGO第五次科学运行（S5）前8个月的数据已被用于此次搜索，该搜索基于应变功率求和的半相干方法（PowerFlux）。没有观测到周期性引力辐射的证据，我们报告了在搜索范围内任何未知的孤立旋转中子星发出的辐射的95%置信度上限。在200 hz波段内获得了低于10−24的应变极限，并且在整个搜索波段上，灵敏度的提高使采样的空间体积平均增加了约100倍。对于标称赤道椭圆率为10−6的中子星，搜索对500 pc的距离很敏感——这个范围可以包含许多未被发现的中子星，尽管其中只有一小部分可能旋转得足够快，可以被LIGO探测到。这个椭圆率的上限被认为是常规中子星所能承受的，而远低于奇夸克星所能承受的最大值。
We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50 – 1100 Hz and with the frequency's time derivative in the range −5 × 10 −9 – 0 Hz s −1. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semi-coherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10 −24 are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10 −6 , the search is sensitive to distances as great as 500 pc—a range that could encompass many undiscovered neutron stars, albeit only a tiny fraction of which would likely be rotating fast enough to be accessible to LIGO. This ellipticity is at the upper range thought to be sustainable by conventional neutron stars and well below the maximum sustainable by a strange quark star.