Supermassive black holes ( SMBHs ) found in the centers of many galaxies are understood to play a fundamental , active role in the cosmological structure formation process .
In hierarchical formation scenarios , SMBHs are expected to form binaries following the merger of their host galaxies .
If these binaries do not coalesce before the merger with a third galaxy , the formation of a black hole triple system is possible .
Numerical simulations of the dynamics of triples within galaxy cores exhibit phases of very high eccentricity ( as high as e \sim 0.99 ) .
During these phases , intense bursts of gravitational radiation can be emitted at orbital periapsis , which produces a gravitational wave signal at frequencies substantially higher than the orbital frequency .
The likelihood of detection of these bursts with pulsar timing and the Laser Interferometer Space Antenna ( LISA ) is estimated using several population models of SMBHs with masses \gtrsim 10 ^ { 7 } ~ { } { M _ { \odot } } .
Assuming 10 % or more of binaries are in triple systems , we find that up to a few dozen of these bursts will produce residuals > 1 ns , within the sensitivity range of forthcoming pulsar timing arrays ( PTAs ) .
However , most of such bursts will be washed out in the underlying confusion noise produced by all the other ’ standard ’ SMBH binaries emitting in the same frequency window .
A detailed data analysis study would be required to assess resolvability of such sources .
Implementing a basic resolvability criterion , we find that the chance of catching a resolvable burst at a one nanosecond precision level is 2 - 50 % , depending on the adopted SMBH evolution model .
On the other hand , the probability of detecting bursts produced by massive binaries ( masses \gtrsim 10 ^ { 7 } { M } _ { \odot } ) with LISA is negligible .