1. Search for Ringdowns in LIGO S4 Data
Lisa M. Goggin, Caltech
with Duncan Brown and Alan Weinstein
1st VESF School in Gravitational Waves
Cascina, Italy, May

2. Black Hole Ringdowns
3 phases of binary coalescence: inspiral, merger, ringdown
We are looking for gravitational waves from black hole ringdowns
Searching LIGO S4 data, (S4: Feb 22 - Mar 23, 2005)
Picture Credit: Kip Thorne
Known waveforms Use matched filtering
1st VESF School, 05/24/06

3. Ringdown Template
The template we use is a damped sinusoid with characteristic frequency, f0 and quality factor, Q.
Gravitational waves have unknown amplitude, arrival time, initial phase
1st VESF School, 05/24/06

4. Template Bank Construct bank of templates according to metric:
Creighton (1999), Owen(1995)
Range motivated by LIGO detector sensitivities
Or, in terms of star’s physical parameters
1st VESF School, 05/24/06

5. Range of Fourth LIGO Science Run
Optimally oriented source
Single detector signal-to-noise ratio = 8
Spin a = 0.9
For M=230Msun, sensitive to black hole ringdowns at a distance of
Hanford 4km: 400 Mpc
Hanford 2km: 150 Mpc
Livingston 4km: 300 Mpc
1st VESF School, 05/24/06