An All-Sky Search for Continuous Gravitational Waves.

Gravitational Waves;LIGO;Physics;Science;Physics

Dergachev, VladimirStoev, Stilian Atanasov ;

University of Michigan

关键词: Gravitational Waves;    LIGO;    Physics;    Science;    Physics;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/64817/volodya_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Gravitational radiation is a direct consequence of general relativity, yet to this day only indirectconfirmation of its existence has been obtained.LIGO is an experiment that aims to detect gravitational waves by comparing the lengths of the two arms of Michelson interferometers.It has recently reached design sensitivity, and a number of searches for intermittent and continuous signals are underway.In particular, isolated rotating neutron stars are expected to emitgravitational radiation ofnearly constant frequency and amplitude. Because the gravitational wave signal amplitudes are thought tobe extremely weak, long time integrations must be carried out to detect asignal. The search is complicated by the motion of the Earth (daily rotation andorbital motion) which induces substantial modulations of detected frequency andamplitude that are highly dependent on source location. Large amounts ofacquired data make this search computationally difficult.We describe our search for such signals using an algorithm called PowerFlux and provide upper limits. In particular, at 153 Hz we obtain a sensitivity of 4.25E-25 for circularly polarized sources in the polar sky region. At a signal frequency of 1100 Hz we are sensitive to neutron stars of ellipticity of ~1E-6 at distances up to 500 pc.We also describe a prototype for a high-sampling-rate wavefront camera that can be used to monitor laser beam characteristics at radio frequencies.