A Search for Gravitational Radiation from PSR 1937+214

Physics;Computer Science

Hereld, Mark ; Drever, Ronald W. P.

University:California Institute of Technology

Department:Physics, Mathematics and Astronomy

关键词: Physics;    Computer Science;   

Others  :  https://thesis.library.caltech.edu/11256/2/Hereld_M_1984.pdf

美国|英语

来源: Caltech THESIS

【 摘 要 】

A search for gravitational radiation from the "millisecond pulsar", PSR1937+214, using a 40 meter baseline laser interferometric detector is described.Four days of observation yielded 1.2 x 10⁵ seconds of data. Throughout the experiment,the pulsar phase was synthesized to an accuracy of better than one tenthof the pulsar period. A trigger generated from this signal synchronized the dataaveraging. Narrow band amplitude spectra centered at the pulsar's fundamentalelectromagnetic pulsation frequency (~642 Hz) and its first harmonic wereobtained. The spectra, one for each combination of polarization and center frequency,place 99.7% confidence level limits on the emitted gravitational radiation.In dimensionless strain, h, the rms limits are:

642 Hz "plus" polarization 1.6 x 10^-17

" "cross" " 3.1 x 10^-17

1294 Hz "plus" polarization 1.1 x 10^-17

" "cross" " 1.5 x 10^-17

Over the four day observing period, the performance of the detector variedwith changing temperature. During the stable night hours, the two optical cavitiesremained locked to reflection minima for 20 to 80 minutes before momentarilylosing lock. Temperature changes of 1° to 2°C in the morning and eveningnecessitated compensating adjustments to the optics to maintain good fringevisibility.

The interferometer senses changes in the separations between three testmasses. The test masses hang like pendulums so that they are free to move inresponse to gravitational radiation. The suspension system is designed to providepassive isolation from seismic and environmental vibration noise. Theorientation of each test mass is stabilized with a feedback loop. The design ofthe test masses, their suspension systems, and the servo system which controlstheir orientation is described.