Radio Properties of Rotating Radio Transients: Single Pulse Spectral and Wait Time Analyses

TL;DR

This study analyzes 11 years of single-pulse data from three RRATs, revealing their spectral indices, pulse clustering, and energy distributions, providing new insights into their emission properties and differences from other pulsars.

Contribution

First spectral analysis of RRAT single-pulses showing their spectral indices and pulse clustering behavior, with implications for understanding their emission mechanisms.

Findings

RRAT spectral indices within pulsar range

Pulses cluster around specific wait-times

Pulse energies follow log-normal distributions

Abstract

Rotating radio transients (RRATs) are a sub-class of pulsars characterized by sporadic emission and thus can generally only be studied by analysis of their single-pulses. Here we present a single-pulse analysis using 11 years of timing data at 1400~MHz of three RRATs, PSRs~J1819$-$1458, J1317$-$5759, and J1913$+$1330. We perform a spectral analysis on the single-pulses of these RRATs for the first time, finding their mean spectral indices to be $-1.1 \pm 0.1$, $-0.6 \pm 0.1$, and $-1.2 \pm 0.2$ respectively, within the known range of pulsar spectral indices. We find no evidence for narrowband features as seen for FRB~121102. However, we find the spread of single-pulse spectral indices for these RRATs (ranging from $-7$ to $+4$) to be larger than has been seen in other pulsars, with the exception of the Crab pulsar. We also analyze the time between detected pulses, or wait-time, and find that the pulses are not random and cluster around wait-times of a few pulse periods as well as $\sim 25$ pulse periods for PSRs~J1819$-$1458 and J1317$-$5759. Additionally we find that there is no correlation between the wait-time and pulse flux density. Finally we find that the distribution of the pulse energy for PSRs~J1317$-$5759 and J1913$+$1330 are log-normal, while that of PSR~J1819$-$1458 is log-normal with possible evidence of an additional power-law component.