Modern Pulsar Timing Array Sensitivity Curves*

As pulsar timing arrays (PTAs) get closer than ever to observing gravitational waves, it is important that we are able to characterize the noise in these galactic-scale detectors. Sensitivity curves, constructed using the power spectral density of the noise in a detector, together with its response to gravitational waves, are used by the gravitational-wave community to characterize sensitivity to a particular kind of signal. While these sensitivity curves are detailed for ground-based and space-based detectors, those for PTAs are often presented in the form of a pie wedge, basically describing the white noise limitations on detection of gravitational waves.

Characterization of the various sources of noise in our pulsars has evolved to a point where different types of white noise and low-frequency time-correlated (red) noise can be accounted for in our gravitational wave searches. Here we report on our investigations of calculating more realistic sensitivity curves for pulsar timing arrays using data from the North American Nanohertz Observatory for Gravitational Waves to provide the noise power spectral density.