First study of subpulse drifting in PSR J1824−0132 based on FAST observations

ABSTRACT This paper presents the first report of subpulse drifting in PSR J1824–0132 using the ultra-high-sensitivity observations from the Five Hundred-meter Aperture Spherical Radio Telescope (FAST). The L-band observations from FAST reveal that the single pulse radiation of PSR J1824–0132 shows periodic amplitude modulation and subpulse drifting, which has not been observed previously. The amplitude modulations shows two different periods $P_3 = 12.15 \pm 0.05 \, \rm P$ and $P_3 = 3.04 \pm 0.01\, \rm P$. A subpulse drifting phenomenon is detected in the radiation mode with the longer amplitude modulation period. The measured drifting period and drift rate are $P_2 = 16.4 \pm 1.3\, \rm P$ and $1.35 \pm 0.11$, respectively. The subpulse drifting has not significant frequency behaviour within the bandpass of 1050–1450 MHz. The pulse nulling phenomenon was investigated using a Markov chain Monte Carlo method, and no pulse nulling phenomenon was found. The studies of this paper expanded the number of pulsars with periodic amplitude modulation and subpulse drifting, which will contribute to the future studies on the statistical properties of subpulse drifting as well as its radiation mechanisms.