Gravitational Pulse Astronomy
  Thompson has argued that the Kozai mechanism is primarily responsible for
driving white-dwarf binary mergers and so generating type Ia supernovae (SNe).
If so, the gravitational wave signal from these systems will be characterized
by isolated repeating pulses that are well approximated by parabolic
encounters. I show that it is impossible to detect these with searches based on
standard assumptions of circular binaries, nor could they be detected by
analogs of the repeating-pulse searches that have been carried out at higher
frequencies, even if these were modified to barycentric time as a function of
putative sky position. Rather, new search algorithms are required that take
account of the intrinsic 3-body motion of the source as well as the motion of
the Earth. If these eccentric binaries account for even a modest fraction of
the observed SN rate, then there should be of order 1 pulse every 20 seconds
coming from within 1 kpc, and there should be of order 200 detectable sources
in this same volume. I outline methods of identifying these sources both to
remove this very pernicious background to other signals, and to find candidate
SN Ia progenitors, and I sketch practical methods to find optical counterparts
to these sources and so measure their masses and distances.
