Investigation of individual pulse emission behaviours from pulsar J1741$-$0840

TL;DR

This study provides a detailed analysis of individual pulse behaviors from pulsar J1741-0840, revealing nulling, subpulse drifting, and periodicities, which enhance understanding of pulsar emission mechanisms.

Contribution

It offers new insights into the pulse emission behaviors, nulling fraction, and subpulse drifting phenomena of pulsar J1741-0840, with detailed observational analysis and fluctuation spectral results.

Findings

Nulling fraction of 23±2% was determined.

Detected two main periodicities at ~32 and 5 rotation periods.

Observed subpulse drifting with a longitudinal separation of about 5 degrees.

Abstract

We have carried out a detailed study of individual pulse emission from the pulsar J1741$-$0840 (B1738$-$08), observed using the Parkes and Effelsberg radio telescopes at the $L$ band. The pulsar exhibits four emission components which are not well resolved by employing multi-component Gaussian fitting. The radio emission originates at a height of approximately 1000 km, with the viewing geometry characterized by inclination and impact angles roughly estimated at 81$^\circ$ and 3$^\circ$, respectively. Fluctuation spectral analysis of single pulse behaviour reveals two prominent periodicities, around 32 and 5 rotation periods. The longer periodic modulation feature is linked to nulling behaviour across the entire emission window, with an updated nulling fraction of 23$\pm$2\% is derived from pulse energy distribution via Gaussian mixture modeling. In addition to quasiperiodic nulling, the pulsar also exhibits the presence of subpulse drifting in the trailing component, with the shorter periodic feature in the fluctuation spectra related to the phenomenon of subpulse drifting, and the longitudinal separation estimated to be about 5 degrees. Both periodic modulations show significant temporal evolution with time-dependent fluctuation power. The ramifications for understanding the radio emission mechanisms are discussed.