Rotating radio transients (hereafter RRATs) were discovered during single-pulse searches of Parkes multibeam pulsar survey data. RRATs are rotating neutron stars detectable only through their single pulses and not through standard Fourier techniques — making them very difficult to both discover and monitor. While it is generally accepted that RRATs are a manifestation of the pulsar phenomenon, many theories have been put forward to explain why RRATs show different emission behavior from other pulsars. RRATs may be just one extreme of the neutron star intermittency spectrum, which sits as the extension of nulling pulsars with extremely high nulling fractions, possibly caused by material fallback from a supernova debris disk or infalling circumstellar material.

Agarwal et al. present the RRATalog, an up-to-date catalogue of 335 known RRATs. For 105 RRATs, only a few pulses, or sometimes just one, have been detected. In such cases it is not possible to deduce the spin period. Of the 230 other RRATs for which a spin period has been determined, only 54 RRATs have sufficient detections to enable measurement of both the period and period-derivative. The authors utilize a uniform sample of RRATs discovered in four Parkes telescope surveys to model their Galactic population. They find the underlying period distribution is significantly shifted toward longer periods compared to canonical pulsars, suggesting RRATs represent a more evolved population. The implied birth rate of < 1.4 RRATs per century is consistent with the Galactic core-collapse supernova rate, suggesting RRATs can be reconciled with known progenitor rates without requiring a separate evolutionary origin.

The figure above is a Mollweide projection showing the Galactic distribution of RRATs. The symbols in the legend represent the discovery telescope. Many sources can be seen along the Galactic plane; this likely reflects that, similar to pulsars, the RRAT number density is higher in the Galactic plane and also that a number of surveys so far have targeted the Galactic plane.