Periodic nulling and even-odd modulation properties of PSR J2313+4253
Abstract
Amplitude modulation of subpulses has substantial research implications for elucidating the geometric structure and emission process of pulsars. Previous studies have revealed that the single-pulse sequence of PSR J2313+4253 exhibits amplitude modulation with periodicities of 44 and 2 rotation periods. Moreover, shorter periodicity is associated with the even-odd modulation phenomenon, but its physical origin is unclear. We performed a detailed study of individual-pulse emission properties from the pulsar J2313+4253, observed at 2250 MHz using the Jiamusi 66 m radio telescope in this study. Using longitude-resolved, harmonic-resolved and two-dimensional fluctuation spectral techniques, we find that the even-odd modulation originates from short-period subpulse drifting, which exhibits considerable temporal dependence. The analysis reveals that the even-odd modulation phenomenon may be attributed to the aliasing effect caused by overlapping sub-beams within the radiation zone due to unclear boundaries during the sparking discharge process in the pulsar magnetosphere.
