Joris Verbiest (Swinburne University of Technology)

Pulsar Timing and the Gravitational Wave Background - Joris Verbiest Colloquium

ATNF Marsfield Lecture Theatre

Abstract

The high stability of some millisecond pulsars (MSPs), along with ever increasing levels of timing precision, has been predicted to enable detection of gravitational wave (GW) effects on the Earth. Specifically, it has been shown that GWs arising from hierarchical galaxy formation - and associated supermassive black hole binaries - would be detected provided 20 MSPs can be timed for five years or more at a precision of ~100 ns. The practical feasibility of this scenario is investigated.

We present results from a long-term timing campaign at the Parkes radio observatory, for the first time providing insights into the timing stability of a large number of MSPs (20). On one of our sources we obtain 200 ns timing precision, which is a first over timescales of a decade or more. More than half of our sample displays stability at current levels of timing precision and a simple analysis on some of our brightest sources demonstrates the potential for sub-100 ns timing.

Using these results, we evaluate the potential for timing array efforts on the major radio telescopes of the world and are cautiously optimistic about the potential for a GW detection within the coming decade.