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

Understand

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 $0.008-5$ $\mu$Hz.
• We use two algorithms in the analysis, including a spectral fitting method and a Bayesian approach.