Doppler Tracking, Pulsar Timing and the Sensitivity of Low-Frequency Gravitational Wave Searches

Speaker(s): John Armstrong (’69)

Gravitational waves (GWs) are predicted across a spectrum ranging from ~kilohertz to femtohertz. Gravity wave detections and subsequent detailed waveform study will give information on astrophysical sources unavailable with any other method. The GW spectrum divides into Fourier bands, depending on detector technology. In the low-frequency (~millihertz) and very-low-frequency (~nanohertz) bands, detectors involve spacecraft Doppler tracking and pulsar timing, respectively. This talk reviews JPL work on these two detection methods, shows how to calculate GW sensitivities in the LF and VLF bands, and discusses the instrumental and other improvements required to achieve detections in these bands.