We present the analysis of between 50 and 100 h of coincident interferometric strain data used to search for and establish an upper limit on a stochastic background of gravitational radiation. These data come from the first LIGO science run, during which all three LIGO interferometers were operated over a 2-week period spanning August and September of 2002. The method of cross correlating the outputs of two interferometers is used for analysis. We describe in detail practical signal processing issues that arise when working with real data, and we establish an observational upper limit on a [Formula Presented] power spectrum of gravitational waves. Our 90% confidence limit is [Formula Presented] in the frequency band 40–314 Hz, where [Formula Presented] is the Hubble constant in units of 100 km/sec/Mpc and [Formula Presented] is the gravitational wave energy density per logarithmic frequency interval in units of the closure density. This limit is approximately [Formula Presented] times better than the previous, broadband direct limit using interferometric detectors, and nearly 3 times better than the best narrow-band bar detector limit. As LIGO and other worldwide detectors improve in sensitivity and attain their design goals, the analysis procedures described here should lead to stochastic background sensitivity levels of astrophysical interest. © 2004 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review D - Particles, Fields, Gravitation and Cosmology
Abbott, B., Abbott, R., Adhikari, R., Ageev, A., Allen, B., Amin, R., Anderson, S., Anderson, W., Araya, M., Armandula, H., Asiri, F., Aufmuth, P., Aulbert, C., Babak, S., Balasubramanian, R., Ballmer, S., Barish, B., Barker, D., Barker-Patton, C., Barnes, M., Barr, B., Barton, M., Bayer, K., Beausoleil, R., Belczynski, K., Bennett, R., Berukoff, S., Betzwieser, J., Bhawal, B., Bilenko, I., Billingsley, G., Black, E., & Blackburn, K. (2004). Analysis of first LIGO science data for stochastic gravitational waves. Physical Review D - Particles, Fields, Gravitation and Cosmology, 69 (12) https://doi.org/10.1103/PhysRevD.69.122004