Searching for Continuous Gravitational Waves in the Parkes Pulsar Timing Array Data Release 3

Abstract

We present results from an all-sky search for continuous gravitational waves from individual supermassive binary black holes using the third data release of the Parkes Pulsar Timing Array (PPTA). Even though we recover a common-spectrum stochastic process, potentially induced by a nanohertz gravitational-wave background, we find no evidence of continuous waves. Therefore, we place upper limits on the gravitational-wave strain amplitude: in the most sensitive frequency range around 10 nHz, we obtain a sky-averaged 95% credibility upper limit of ≈ 7 × 10−15. Our search is sensitive to supermassive binary black holes with a chirp mass of ≥109 M⊙ up to a luminosity distance of 50 Mpc for our lea..