A study of periodic single-pulse emission behavior in PSR J1819+1305 using L-band observations from the FAST

This paper reports a detailed study of the single pulses of PSR J1819+1305 using L-band observations from the FAST. Using the unprecedented ultra-high sensitivity of FAST, we observed PSR J1819+1305 to estimate its nulling period and fraction, identify its pulse nulling and burst states, and analyze its subpulse drifting, pulse profile and polarization properties. Based on the analysis of polarization, the magnetospheric configuration was constrained, and the emission heights were estimated. Our study reveal that single pulse of this pulsar displays a periodic nulling with a nulling fraction of ∼32.9% and nulling period of 50P1. Both values are smaller than those obtained from previous low-frequency (327 MHz, 430 MHz) observations. Analyses of single-pulse energy temporal variations further indicate notable differences in the average pulse profile geometries between the last burst pulse preceding the nulling state and the first burst pulse following it. Within the trailing component, we detected subpulse drifting with a period of P2 = 2.08 ± 0.03P1 and amplitude modulation with a period of P3 = 6.65 ± 0.04P1, where P1 is spin period of PSR J1819+1305. Additionally, we determine the magnetic inclination angle α ≈ 131.36○ and impact angle β ≈ 3.36○ of this pulsar using the RVM model and MCMC method, and further derive emission heights of rgeo = 735.76 ± 11.00 km and rdelay = 782.36 ± 77.39 km via the emission geometry and aberration-retardation correction methods, respectively. This study expands the multi-band observational sample of pulsars with periodic nulling, amplitude modulation, and subpulse drifting, thereby laying a foundation for future studies of statistical and radiation mechanism.