Detection of hidden emissions in two rotating radio transients with high surface magnetic fields

TL;DR

This study reveals hidden, weak radio emissions in two high magnetic field RRATs, suggesting they may constitute a new pulsar class distinct from known types, based on high-sensitivity observations and polarization analysis.

Contribution

The paper provides the first detection of sequential weak emissions in high magnetic field RRATs, indicating a potential new pulsar subclass with unique emission properties.

Findings

Weak emissions contribute small fractions to total energy

Weak emissions are significantly fainter than single pulses

Polarization suggests intermittent magnetospheric processes

Abstract

Rotating Radio Transients (RRATs) are neutron stars emitting sporadic radio pulses. The unique emission of RRATs has been proposed to resemble those of known pulsar types, such as extreme nulling pulsars or pulsars with giant pulses. However, the presence of additional radiation beyond these sporadic pulses remains unclear. Through high-sensitivity observations and extended tracking, we detected the sequential weak emissions in two RRATs with relatively high surface magnetic fields (Bs > 10^13 G): J1846-0257 and J1854+0306. These emissions show peak flux densities of 0.15 and 0.41 mJy, up to 687 and 512 times weaker than our detected RRAT single pulses, respectively. The weak emissions contribute small fractions (~ 16% and 5%) to the total radio pulse energy releases, contrasting significantly with giant-pulse pulsars where normal pulses dominate. Polarization analysis of J1854+0306 suggests that its sporadic RRAT pulses may originate from intermittent enhanced sparking processes due to magnetospheric evolution. Our findings indicate that some RRATs may represent a novel class of pulsars, distinct from any previously known subclass. Further observations of sources with similar rotational properties using high-sensitivity instruments could validate the generality of these hidden emissions.