The unusual emission from PSR B1859+07 with FAST

TL;DR

This study uses FAST to analyze PSR B1859+07's unusual emission modes, revealing mode changes, a new emission shift event, and similar polarization properties across modes, enhancing understanding of pulsar emission behaviors.

Contribution

First detailed simultaneous broad-band observations of PSR B1859+07's abnormal emission modes, including discovery of a new emission shift event and polarization analysis.

Findings

Confirmed three emission modes, including a new shift event.

Identified a quasi-periodicity of 155 pulses in mode changes.

Found similar polarization angles across all modes.

Abstract

We present simultaneous broad-band radio observations on the abnormal emission mode from PSR B1859$+$07 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). This pulsar shows peculiar emission phenomena, which are occasional shifts of emission to an early rotational phase and mode change of emission at the normal phase. We confirm all these three emission modes with our datasets, including the B (burst) and Q (quiet) modes of the non-shift pulses and the emission shift mode with a quasi-periodicity of 155 pulses. We also identify a new type of emission shift event, which has emission at the normal phase during the event. We studied polarisation properties of these emission modes in details, and found that they all have similar polarisation angle (PA) curve, indicating the emission of all these three modes are from the same emission height.