Doctor of Philosophy (PhD)


Physics and Astronomy

Document Type



Gravitational waves are ripples in space-time itself, predicted by Einstein's General theory of relativity, which propagate at the speed of light and are not scattered or extinguished by passing through matter almost at all. In particular, the gravitational waves from the coalescences of binary systems of compact objects, such as neutron stars and black holes, are exciting prospects for observation. The Laser Interferometer Gravitational-wave Observatory experiment intends to make the _x000C_first direct measurement of gravitational waves, and use the results to uncover new astrophysics. These observations will not be limited by extinction from dust and gas, and will probe astrophysical systems at distances of tens of millions to hundreds of millions of parsecs. The LIGO Scienti_x000C_c Collaboration searches for gravitational waves from a variety of astrophysical sources amongst this data. These searches are complicated by the presence of transients of non-astrophysical origin in the interferometer data. Control system and equipment malfunctions, as well as coupling from ground motions and electromagnetic fields, are the most common noises that detract from the LIGO data quality. These sources of noise increase the false alarm rate for gravitational wave searches, and need to be vetoed to search the data effectively for detections, or to set upper limits properly. Vetoes for the searches are created from the available data quality information, and their e_x000B_ect on the overall sensitivity of LIGO to these sources must be analyzed. During the S5 science run, I evaluated the data quality information for use as vetoes for the LIGO search for compact binary coalescences. The use of these vetoes made this search more sensitive to distant gravitational radiation sources by decreasing the non-astrophysical background from noise transients. In this dissertation, I quantify the impact of data quality on searches for gravitational waves with LIGO, and the resulting increased sensitivity to binary coalescing systems.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

González, Gabriela