Detection of Gravitational Wave Emission by Supermassive Black Hole
  Binaries Through Tidal Disruption Flares
  Galaxy mergers produce supermassive black hole binaries, which emit
gravitational waves prior to their coalescence. We perform three-dimensional
hydrodynamic simulations to study the tidal disruption of stars by such a
binary in the final centuries of its life. We find that the gas stream of the
stellar debris moves chaotically in the binary potential and forms accretion
disks around both black holes. The accretion light curve is modulated over the
binary orbital period owing to relativistic beaming. This periodic signal
allows to detect the decay of the binary orbit due to gravitational wave
emission by observing two tidal disruption events that are separated by more
than a decade.
