The L -band Radio Emission Properties of PSR J0612+3721 with FAST Observations

This paper reports a detailed single-pulse study of PSR J0612+3721 using ultrahigh sensitivity L -band observations from the Five-hundred-meter Aperture Spherical Radio Telescope (FAST). Our results show that the radio emission of this pulsar displays regular subpulse drifting, which is dominated by negative drifting with occasional direction reversals over specific time intervals. The drift characteristic parameters P 2 and P 3 are measured with the two-dimensional fluctuation spectrum (2DFS) method, and the values are −0.25 P 1 and 27.58 P 1 for negative drifting and 0.25 P 1 and 18.17 P 1 for positive drifting, respectively. Statistical analysis of single-pulse energy confirms the absence of pulse nulling. We divided the FAST observational data into eight subbands to construct multiband pulse profiles and further investigated frequency-dependent behavior and phase-resolved spectra of profile. Pulse widths at the 50% peak intensity levels reveal that the pulse width increases with increasing emission frequency, contrary to that observed in most pulsars. Comparative analysis of profiles in positive and negative drifting states shows that there are no distinct morphological differences between the two states. Phase-resolved spectral analysis indicates that the trailing component of the profile has stronger high-frequency emission, whereas the leading component shows opposite radiation property. Furthermore, we also detected a weak emission component with mode-switching behavior at the trailing edge of the profile. These peculiar observational phenomena will enrich the understanding of the diversity of radio emission and provide new insights into the emission mechanism of pulsars.