The Sensitivity of the Parkes Pulsar Timing Array to Individual Sources
  of Gravitational Waves
  We present the sensitivity of the Parkes Pulsar Timing Array to gravitational
waves emitted by individual super-massive black-hole binary systems in the
early phases of coalescing at the cores of merged galaxies. Our analysis
includes a detailed study of the effects of fitting a pulsar timing model to
non-white timing residuals. Pulsar timing is sensitive at nanoHertz frequencies
and hence complementary to LIGO and LISA. We place a sky-averaged constraint on
the merger rate of nearby ($z < 0.6$) black-hole binaries in the early phases
of coalescence with a chirp mass of $10^{10}\,\rmn{M}_\odot$ of less than one
merger every seven years. The prospects for future gravitational-wave astronomy
of this type with the proposed Square Kilometre Array telescope are discussed.
