We provide an analysis of timing irregularities observed for 366 pulsars.
Observations were obtained using the 76-m Lovell radio telescope at the Jodrell
Bank Observatory over the past 36 years. These data sets have allowed us to
carry out the first large-scale analysis of pulsar timing noise over time
scales of > 10yr, with multiple observing frequencies and for a large sample of
pulsars. Our sample includes both normal and recycled pulsars. The timing
residuals for the pulsars with the smallest characteristic ages are shown to be
dominated by the recovery from glitch events, whereas the timing irregularities
seen for older pulsars are quasi-periodic. We emphasise that previous models
that explained timing residuals as a low-frequency noise process are not
consistent with observation.Comment: Accepted by MNRAS. High resolution images available from the article
on AD