# Radio emission features in different modes of PSR J0826+2637 (B0823+26)

## TL;DR

This study provides a detailed analysis of the radio emission modes of pulsar J0826+2637, revealing mode-dependent nulling, periodic fluctuations, and intensity variations, enhancing understanding of pulsar emission behavior at low radio frequencies.

## Contribution

It is the first detailed multi-mode analysis of PSR J0826+2637 at 306-339 MHz, identifying mode-specific nulling, periodicity, and emission features, and their transitions.

## Key findings

- Nulling varies from a few percent in B-mode to over 90% in Q-mode.
- Periodic fluctuations are observed in main pulse and postcursor during B-mode.
- Significant intensity increase during transition from Q-mode to Q-bright mode.

## Abstract

We report on a detailed analysis of the radio emission during the different modes of the pulsar J0826+2637 (B0823+26), observed using the Giant Meterwave Radio Telescope at 306-339 MHz observing frequencies. The pulsar profile has a postcursor and interpulse emission in addition to the main pulse. The single pulses showed the presence of nulling, periodic fluctuation in the emission as well as two prominent modes. In addition the pulsar also showed the presence of a null state where no emission was seen for roughly an hour which was immediately followed by a short duration ($\sim$5 minutes) bright state termed the Q-bright state. The nulling varied significantly in the two modes, from a few percent nulls in B-mode to more than 90 percent nulling during the Q-mode. Additionally, the pulsar showed the presence of low level emission in both the interpulse and postcursor components when the main pulse nulled in B-mode. We detected periodic fluctuations in both the main pulse and postcursor during B-mode which were most likely a form of periodic amplitude modulation unrelated to subpulse drifting. We have also detected the appearance of periodicity during the transitions from the null to the burst states in the Q-mode, which was longer than the B-mode modulations. Our analysis further revealed a significant increase in the main pulse and post-cursor intensity during the transition from the Q-mode to the short duration Q-bright mode. On the other hand no commensurate variation was visible in the interpulse intensity.