Modal Sequencing and Dynamic Emission Properties of an 8-hour GMRT Observation of Pulsar B1822-09

TL;DR

This study analyzes an 8-hour GMRT observation of pulsar B1822-09, revealing complex emission behaviors and mode transitions that suggest interconnected magnetospheric processes.

Contribution

It uncovers three new emission behaviors and provides detailed insights into the pulsar's pulse structure and mode transition mechanisms.

Findings

Discovery of three new emission behaviors in B1822-09

Complex pulse structure with triple cone/core configuration

Mode changes facilitate information transfer between magnetic poles

Abstract

The research presented here examines an 8-hour observation of pulsar B1822-09,taken by the Giant Metrewave Radio Telescope. B1822-09 has been known to exhibit two stable emission modes, the B-mode, where the precursor (PC) `turns-on', and the Q-mode, which is defined by interpulse (IP) emission. The results of our analysis, of this extremely long observation, have shown that B1822-09 exhibits at least three other emission behaviors that have not been seen before in other similar pulsars or in other observations of B1822-09. These three behaviors can be described as: Q-mode emission with PC emission, B-mode emission with IP emission, and instances where both the PC and IP are `on' when transitioning from one mode to the other. The pulse structure has been found to be more complex than previously thought. The MP has an inner cone/core triple (T) configuration together with a central sightline traverse. The IP is a 15/degr-wide region, that along with the MP originate from an open dipolar field. The PC emission comes from a still unknown source. We argue that the PC emission arises within the same region as the MP, but likely comes from higher in the magnetosphere. Overall, our analyses strongly suggest that mode changes allow information transfer between the two magnetic polar regions and contribute to global magnetospheric changes.