Search for gravitational waves from black-hole ringdowns using TAMA300 data

We report recent results of a search for gravitational waves radiated by black-hole ringdowns using TAMA300 data. A matched-filter search was performed for the data obtained in the observations in 2001 and 2003. A typical signal-to-noise ratio is expected to be 100 for a ringdown event at a distance of 10 kpc from the detector in the direction of maximum sensitivity. Our Monte Carlo study shows that the detection probability for Galactic ringdowns is 50-60% for black holes with masses greater than 25Mo-dot. Vetoing techniques for event selection and noise reduction are also studied. We found that by examining profiles of filter outputs, about 90% of spurious events arising from external disturbances or detector noises can be discriminated with the false dismissal probability of 5%