An Einstein@home search for continuous gravitational waves from Cassiopeia A
Sylvia J. Zhu, Maria Alessandra Papa, Heinz-Bernd Eggenstein, Reinhard Prix, Karl Wette, Bruce Allen, Oliver Bock, David Keitel, Badri Krishnan, Bernd Machensch… 展开作者
Sylvia J. Zhu, Maria Alessandra Papa, Heinz-Bernd Eggenstein, Reinhard Prix, Karl Wette, Bruce Allen, Oliver Bock, David Keitel, Badri Krishnan, Bernd Machenschalk, Miroslav Shaltev, Xavier Siemens
We report the results of a directed search for continuous gravitational-wave emission in a broad frequency range (between 50 and 1000 Hz) from the central compact object of the supernova remnant Cassiopeia A (Cas A). The data comes from the sixth science run of LIGO and the search is performed on the volunteer distributed computing network Einstein@Home. We find no significant signal candidate, and set the most constraining upper limits to date on the gravitational-wave emission from Cas A, which beat the indirect age-based upper limit across the entire search range. At around 170 Hz (the most sensitive frequency range), we set 90% confidence upper limits on the gravitational wave amplitude $h_0$ of $\sim\!\!~2.9\times 10^{-25}$, roughly twice as constraining as the upper limits from previous searches on Cas A. The upper limits can also be expressed as constraints on the ellipticity of Cas A; with a few reasonable assumptions, we show that at gravitational-wave frequencies greater than 300~Hz, we can exclude an ellipticity of $\gtrsim\!\!~10^{-5}$.
Observational constraints on the spin/anisotropy of the CCOs of Cassiopeia A, Vela Jr. and G347.3-0.5 and a single surviving continuous gravitational wave candidate
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)(马克斯·普朗克引力物理研究所(阿尔伯特·爱因斯坦研究所));Leibniz Universität Hannover(汉诺威莱布尼茨大学)
Results of an all-sky high-frequency Einstein@Home search for continuous gravitational waves in LIGO's fifth science run
我们提出了一个高频全天空搜索的连续引力波从孤立的紧凑的物体在LIGO的第五次科学运行(S5)的数据,使用的计算能力的爱因斯坦@家志愿者计算项目。这是唯一一次专门的连续引力波搜索,在S5数据上探测这种高频范围。我们没有发现显著的候选信号,因此我们对连续引力波应变振幅设置了90%置信水平的上限。在搜索频率范围的较低端,大约1250 Hz,最受约束的上限是$5.0\times 10^{-24}$,而在较高端,大约1500 Hz,它是$6.2\times 10^{-24}$。根据这些上限,并假设主转动惯量的基准值为$10^{38}$ kg $\,$ m $^2$,我们可以排除在地球100 pc范围内,自转周期在1.3和1.6毫秒之间的椭圆率高于大约$2.8\times10^{-7}$的天体。
Results of the deepest all-sky survey for continuous gravitational waves on LIGO S6 data running on the Einstein@Home volunteer distributed computing project
Hierarchical follow-up of sub-threshold candidates of an all-sky Einstein@Home search for continuous gravitational waves on LIGO sixth science run data
Deep Einstein@Home search for Continuous Gravitational Waves from the Central Compact Objects in the Supernova Remnants Vela Jr. and G347.3-0.5 using LIGO public data
The G347.3-0.5 outlier from O3: a follow-up case study for continuous gravitational-wave candidates
Universitat de les Illes Balears(巴利阿里群岛大学);Università di Roma La Sapienza(罗马第一大学);INFN, Sezione di Roma(罗马国家核物理研究所);University of Michigan(密歇根大学);Università di Milano(米兰大学);INFN sezione di Milano(米兰国家核物理研究所);University of British Columbia(不列颠哥伦比亚大学);University of Minnesota(明尼苏达大学);CEDAR Audio Ltd(CEDAR音频有限公司);IGR, University of Glasgow(格拉斯哥大学引力与天体物理研究组);Department of Physics & Astronomy, University of Manitoba(曼尼托巴大学物理与天文系);INFN, Sezione di Ferrara(费拉拉国家核物理研究所);Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences(波兰科学院尼古拉·哥白尼天文学中心)
A new veto for continuous gravitational wave searches
我们提出了一个新的否决程序来区分连续的引力波(CW)信号和探测器的文物,可以模仿他们的行为。否决程序利用了这样一个事实,即一个长期的相干扰动是不太可能比一个真正的信号表现出天体物理起源的多普勒调制。因此,在搜索中存在离群值的情况下,我们在多普勒调制关闭(DM关闭)的情况下围绕离群值的频率执行多步搜索,并将这些结果与原始(DM打开)搜索的结果进行比较。如果来自DM关闭搜索的结果比来自DM打开搜索的结果更显著,则离群值最有可能是由于伪影而不是信号。我们调整否决程序,使其具有非常低的错误驳回率。有了这个否决权,我们能够在最近的全天低频Einstein@Home搜索中识别出6349个候选者中的99.9%以上的相干扰动,这些候选者来自Advanced LIGO O 1观测运行的数据[1]。我们在附录中提供了每种已识别干扰的详细信息。
Einstein@Home all-sky search for periodic gravitational waves in LIGO S5 data
本文介绍了在第五次LIGO科学运行(S5)中对频率范围为[50,1190] Hz、频率导数范围为[-2 x 10^-9,1.1 x 10^-10] Hz/s的周期性引力波进行全天搜索的结果。搜索的新颖性在于使用基于Hough变换的非相干技术来结合来自约一天的时间尺度上的相干搜索的信息。因为这些搜索是非常计算密集型的,它们已经部署在Einstein@Home分布式计算项目基础设施上。这里提出的搜索比之前在早期S5 LIGO数据中进行的Einstein@Home搜索灵敏度高出3倍。后期处理只剩下八个幸存的候选人。我们表明,更深入的后续研究排除了他们中的每一个。因此,由于没有统计上显着的引力波信号已被检测到,我们报告的上限的内在引力波振幅h 0。例如,在152.5 Hz的0.5 Hz宽带中,我们可以排除h 0大于7.6 x 10^-25的信号,置信度为90%。
Probing magnetic fields of compact objects with continuous gravitational waves
Inter University Centre for Astronomy and Astrophysics(大学天文与天体物理中心);Universitat de les Illes Balears(巴利阿里群岛大学);Department of Physics, Indian Institute of Technology Gandhinagar(印度理工学院甘地纳加尔物理系);International Centre for Theoretical Sciences, Tata Institute of Fundamental Research(塔塔基础研究院国际理论科学中心)