160 Hours of Data Taken on the TAMA300

Gravitational Wave Detector

Seiji Kawamura, National Astronomical Observatory of Japan
The TAMA project, the Japanese effort for detecting gravitational waves using the 300m laser interferometer, successfully took 160 hours of data between August 21, 2000 and September 4, 2000. The best sensitivity of the detector was about $5\times10^{-21} {\rm Hz}^{-1/2}$ around 1 kHz in terms of strain, which gives a signal-to-noise ratio of 20 to 30 for gravitational waves emitted from a binary neutron star coalescence in the center of our galaxy. The interferometer was operated remarkably stably; the longest continuous locking time was more than 12 hours, and on one day it was locked for more than 23 hours out of 24 hours. The quality of the data was also drastically improved compared with our previous runs. First the non-stationary noise which appeared very often in the previous data runs was significantly reduced. Secondly approximately 100 signals including feedback and error signals of various control loops and environmental signals such as ground motion were also recorded so that any spurious signals in the interferometer output can be vetoed by correlating them with other channels. The obtained data are now being analyzed for gravitational wave detection as well as for diagnosis purposes of the interferometer. We will further improve the sensitivity and stability of the detector from now until in January 2001 we plan to hold a two-month data run. Please have a look at our home page. http://tamago.mtk.nao.ac.jp/ Also the "Data treatment guideline of TAMA" can be found at the following web site. http://tamago.mtk.nao.ac.jp/tama/data-access.html