The RRATalog: a Galactic census of rotating radio transients

TL;DR

This paper presents the RRATalog, a comprehensive catalogue of 335 rotating radio transients, models their Galactic population, and estimates their total numbers and birth rates, revealing their relation to pulsars and supernovae.

Contribution

The study provides the first uniform population model of RRATs, estimates their total Galactic population, and compares their properties to pulsars and supernova progenitors.

Findings

Estimated 34,000 potentially observable RRATs above 30 mJy kpc$^2$ luminosity.

Population size comparable to canonical pulsars at high luminosities.

RRATs have longer periods and steeper luminosity functions than pulsars.

Abstract

Rotating radio transients (RRATs) represent a significant but poorly understood component of the Galactic neutron star population, characterized by sporadic emission first detectable only through single-pulse searches. We present the RRATalog, an up-to-date catalogue of 335 RRATs, and utilize a uniform sample of RRATs discovered in four Parkes telescope surveys to model their Galactic population. Accounting in detail for observational selection effects, we find a radial density profile similar to pulsars, but identify a significantly steeper luminosity function (power-law index $\alpha \simeq -1.3$) than previously assumed. For sources beaming towards Earth, we estimate $34000 \pm 1600$ potentially observable RRATs above a peak luminosity of 30 mJy kpc$^2$. At these high luminosities, the RRAT population is comparable in size to that of canonical pulsars. Consistent with the observed distribution, the underlying period distribution is significantly shifted toward longer periods compared to canonical pulsars, suggesting RRATs represent a more evolved population. We find evidence for a turnover in the luminosity function below 30 mJy kpc$^2$, and predict that the total number of potentially observable RRATs is $\lesssim 70,000$. Applying the Tauris \& Manchester beaming model, we estimate the total Galactic RRAT population to be $\lesssim 400,000$. The implied birth rate of $\lesssim 1.4$ 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. We provide predictions for RRAT discoveries in ongoing and future surveys.