The gravitational wave signals from coalescing Supermassive Black Hole
Binaries are prime targets for the Laser Interferometer Space Antenna (LISA).
With optimal data processing techniques, the LISA observatory should be able to
detect black hole mergers anywhere in the Universe. The challenge is to find
ways to dig the signals out of a combination of instrument noise and the large
foreground from stellar mass binaries in our own galaxy. The standard procedure
of matched filtering against a grid of templates can be computationally
prohibitive, especially when the black holes are spinning or the mass ratio is
large. Here we develop an alternative approach based on Metropolis-Hastings
sampling and simulated annealing that is orders of magnitude cheaper than a
grid search. We demonstrate our approach on simulated LISA data streams that
contain the signals from binary systems of Schwarzschild Black Holes, embedded
in instrument noise and a foreground containing 26 million galactic binaries.
The search algorithm is able to accurately recover the 9 parameters that
describe the black hole binary without first having to remove any of the bright
foreground sources, even when the black hole system has low signal-to-noise.Comment: 4 pages, 3 figures, Refined search algorithm, added low SNR exampl