Improved timing of the millisecond pulsar PSR 1937+21 using real-time coherent dedispersion

Abstract

Profiles of the millisecond pulsar PSR 1937+21 have been obtained with 6 μs resolution using a real-time hardware dispersion removal device. This dedisperser has a potential resolution of better than 0.5 μs and is immune to time-of-arrival jitter caused by scintillation-induced spectral gradients across the receiver passband. It significantly reduces the time-of-arrival residuals when compared with the timing technique currently in use. This increased timing accuracy, when utilized in a long-term timing program of millisecond pulsars, will improve the solar system ephemeris and will substantially improve the detection limit of a gravitational wave background.