Radio properties of rotating radio transients – I. Searches for periodicities and randomness in pulse arrival times

We have analysed the long- and short-term time dependence of the pulse arrival times and the pulse detection rates for eight rotating radio transient (RRAT) sources from the Parkes Multibeam Pulsar Survey. We find significant periodicities in the individual pulse arrival times from six RRATs. These periodicities range from ∼30 min to 2100 d, and from one to 16 independent (i.e. non-harmonically re...