The Benefits of VLBI Astrometry to Pulsar Timing Array Searches for Gravitational Radiation

Understand

Precision astrometry is an integral component of successful pulsar timing campaigns.

• Astrometric parameters are commonly derived by fitting them as parameters of a timing model to a series of pulse times of arrival (TOAs).
• TOAs measured to microsecond precision over several-year spans can yield position measurements with sub-milliarcsecond precision.
• However, timing-based astrometry can become biased if a pulsar displays any red spin noise, which can be compared to the red noise signal produced by the stochastic gravitational wave background.