Periodic mode changing in PSR J1048-5832

TL;DR

This paper reports the discovery of periodic mode changing in PSR J1048-5832, characterized by amplitude modulation between strong and weak modes in the pulse profile, with a short period of about 2.1 seconds, challenging existing pulsar models.

Contribution

It provides the first evidence of periodic mode changing in PSR J1048-5832 with detailed polarization and spectral analysis, expanding understanding of pulsar emission variability.

Findings

Periodic amplitude modulation observed (~2.1 s period)

Central and trailing components switch modes, leading component remains stable

Modulation not explained by existing models like subpulse drifting

Abstract

By analysing the data acquired from the Parkes 64-m radio telescope at 1369 MHz, we report on the phase-stationary non-drift amplitude modulation observed in PSR J1048-5832. The high-sensitivity observations revealed that the central and trailing components of the pulse profile of this pulsar switch between a strong mode and a weak mode periodically. However, the leading component remains unchanged. Polarization properties of the strong and weak modes are investigated. Considering the similarity to mode changing, we argue that the periodic amplitude modulation in PSR J1048$-$5832 is periodic mode changing. The fluctuation spectral analysis showed that the modulation period is very short (~2.1 s or 17 P1), where P1 is the rotation period of the pulsar. We find that this periodic amplitude modulation is hard to explain by existing models that account for the periodic phenomena in pulsars like subpulse drifting.