Yan Wang^*
School of Physics, Huazhong University of Science and Technology,
1037 Luoyu Road, Wuhan, Hubei Province 430074, China
and MOE Key Laboratory of Fundamental Physical Quantities Measurements,
1037 Luoyu Road, Wuhan, Hubei Province 430074, China
Soumya D. Mohanty^†
Department of Physics, The University of Texas Rio Grande Valley,
One West University Boulevard, Brownsville, Texas 78520, USA
and Center for Gravitational Wave Astronomy, The University of Texas Rio Grande Valley,
One West University Boulevard, Brownsville, Texas 78520, USA.
(Received 4 October 2016; revised manuscript received 29 December 2016; published 12 April 2017)

The advent of next generation radio telescope facilities, such as the Square Kilometer Array (SKA), will usher in an erawhere a pulsar timing array (PTA) based search for gravitationalwaves(GWs) will be able to use hundreds of well timed millisecond pulsars rather than the fewdozens in existing PTAs.Arealistic assessment of the performance of such an extremely large PTAmust take into account the data analysis challenge posed by an exponential increase in the parameter space volume due to the large number of so-called pulsar phase parameters. We address this problem and present such an assessment for isolated supermassive black hole binary (SMBHB) searches using a SKA era PTA containing 103 pulsars.We find that an all-sky search will be able to confidently detect nonevolving sources with a redshifted chirp mass of 10¹⁰ M⊙ out to a redshift of about 28 (corresponding to a rest-frame chirp mass of 3.4 × 10⁸ M⊙).We discuss the important implications that the large distance reach of a SKA era PTA has on GWobservations from optically identified SMBHB candidates. If no SMBHB detections occur, a highly unlikely scenario in the light of our results, the skyaveraged upper limit on strain amplitude will be improved by about 3 orders ofmagnitude over existing limits.

DOI: 10.1103/PhysRevLett.118.151104