1. Advance Warning of Supermassive Black Hole Mergers
Bence Kocsis
PhD student, Eotvos University, Hungary
Advisors:
Zsolt Frei (Eotvos)
Zoltán Haiman (Columbia)
Kristen Menou (Columbia)
1st VESF School on Gravitational Waves,
May 24, 2006; Cascina, Italy

2. Conclusions GW–EM counterpart searches promising:
Typical LISA error box dV = (0.1deg2)x(dz=0.03) contains one quasar (Kocsis et al. 2006)
Time dependent error box analysis
New technique based on Fourier transforms
Above errors available ~20 days ahead of ISCO allowing targeted variability searches

3. How does LISA measure source direction?
Orbital modulation of the GW signal
Detector orientation:
Source direction:
Source orientation:
Amplitude modulation is periodic with

4. Harmonic mode expansion
We expand the modulation in a series of harmonics:
Decoupled angular and time dependence!
Simple analytical result!
Quickly convergent series

5. Parameter Error Estimation
Computed the Fisher matrix as a function of time
The final errors (~0.1deg2) do not change in the final stages of the inspiral.
Marginalized angular and distance errors

6. Implications We’ll have 20 nights in advance!
Monitor variability in 1 deg2 field
Deep survey of all galaxies
photometric redshifts
X-ray luminosity
Choose potential candidates
Monitor X-ray variability