Discovery of an RRAT-like pulsar via its single pulses in an MWA imaging survey

TL;DR

This paper reports the discovery of a pulsar with both RRAT-like sporadic bright pulses and persistent dimmer emissions, revealing a potential new class of pulsars with unique polarization and rotation measure characteristics.

Contribution

The discovery of PSR J0031-5726 via an MWA imaging survey introduces a pulsar exhibiting both RRAT-like and normal pulsar features, suggesting a new intermediate pulsar class.

Findings

Pulsar exhibits sporadic bright pulses and persistent dim emissions.

Bright pulses arrive later and have variable polarization angles.

Rotation measure varies up to 0.8 rad/m^2 between pulses.

Abstract

We report the discovery of PSR J0031$-$5726 in the GaLactic and Extragalactic All-sky MWA eXtended imaging survey at a Galactic latitude of $b \approx -60^\circ$. The pulsar exhibits both sporadic, extremely bright pulses reminiscent of rotating radio transients (RRATs) as well as a persistent, dimmer pulses. The bright pulses tend to arrive at later rotation phases than their dimmer counterparts, and have dramatically varying polarization angle curves, such that the integrated profile appears almost completely depolarized down to the system noise level. The rotation measure of individual pulses was found to sometimes vary by up to ${\sim}0.8\,$rad/m$^2$, but was otherwise generally consistent with its average (ionosphere-corrected) value of $10.0 \pm 0.1\,$rad/m$^2$. We surmise that J0031$-$5726 may represent a class of pulsar that is intermediate between normal pulsars and RRATs.