Improving timing sensitivity in the microhertz frequency regime: limits from PSR J1713+0747 on gravitational waves produced by super-massive black-hole binaries

Research output: Contribution to journalArticle

  • External authors:
  • Benetge Perera
  • Benjamin Stappers
  • S Babak
  • J. Antoniadis
  • Cees Bassa
  • R.N. Caballero
  • D. J. Champion
  • I {Cognard}
  • G Desvignes
  • E. Graikou
  • L. Guillemot
  • Gemma Janssen
  • R. Karuppusamy
  • Michael Kramer
  • Patrick Lazarus
  • L Lentati
  • K. Liu
  • Andrew Lyne
  • James Mckee
  • S. Oslowski
  • D Perrodin
  • Sotirios Sanidas
  • A Sesana
  • G. Shaifullah
  • G Theureau
  • J.P.W. Verbiest
  • S R Taylor


We search for continuous gravitational waves (CGWs) produced by individual super-massive black-hole binaries (SMBHBs) in circular orbits using high-cadence timing observations of PSR J1713+0747. We observe this millisecond pulsar using the telescopes in the European Pulsar Timing Array (EPTA) with an average cadence of approximately 1.6 days over the period between April 2011 and July 2015, including an approximately daily average between February 2013 and April 2014. The high-cadence observations are used to improve the pulsar timing sensitivity across the GW frequency range of 0.008−5 μHz. We use two algorithms in the analysis, including a spectral fitting method and a Bayesian approach. For an independent comparison, we also use a previously published Bayesian algorithm. We find that the Bayesian approaches provide optimal results and the timing observations of the pulsar place a 95 per cent upper limit on the sky-averaged strain amplitude of CGWs to be 3.5×10-13 at a reference frequency of 1 μHz. We also find a 95 per cent upper limit on the sky-averaged strain amplitude of low-frequency CGWs to be 1.4 × 10-14 at a reference frequency of 20 nHz.

Bibliographical metadata

Original languageEnglish
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Issue number1
Early online date2 May 2018
Publication statusPublished - 21 Jul 2018

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