Meterwavelength Single-pulse Polarimetric Emission Survey II: The phenomenon of Drifting Subpulses

TL;DR

This survey of pulsars using fluctuation spectral analysis identified drifting subpulses in nearly half of the sample, revealing three categories of pulsar behavior and their relation to spin-down energy loss, supporting the Partially Screened Gap model.

Contribution

First detailed analysis of drifting subpulses across a large pulsar sample, establishing their dependence on spin-down energy and supporting a specific emission model.

Findings

46% of pulsars show periodic features including drifting subpulses.

Three distinct pulsar categories based on drift behavior.

Anti-correlation between drift periodicity and spin-down energy loss.

Abstract

A large sample of pulsars was observed as part of the Meterwavelength Single-pulse Polarimetric Emission Survey. We carried out a detailed fluctuation spectral analysis which revealed periodic features in 46% pulsars including 22 pulsars where drifting characteristics were reported for the first time. The pulsar population can be categorized into three distinct groups, pulsars which show systematic drift motion within the pulse window, the pulsars showing no systematic drift but periodic amplitude fluctuation and pulsars with no periodic variations. We discovered the dependence of the drifting phenomenon on the spin down energy loss ($\dot{E}$), with the three categories occupying distinctly different regions along the $\dot{E}$ axis. The estimation of the drift periodicity ($P_3$) from the peak frequency in the fluctuation spectra is ambiguous due to the aliasing effect. However, using basic physical arguments we were able to determine $P_3$ in pulsars showing systematic drift motion. The estimated $P_3$ values in these pulsars were anti-correlated with $\dot{E}$ which favoured the Partially Screened Gap model of Inner Acceleration Region in pulsars.