The radio signal of PSR B0950 + 08 is detected over the whole pulse phase

Abstract

ABSTRACT Pulsars are known as the ‘lighthouses’ of the Universe. Periodic pulses with a duty cycle of $\sim 10{{\ \rm per\ cent}}$ are detected when the radio beam of a rotating pulsar sweeps across the telescope. In this report, 160-min data of a nearby pulsar, PSR B0950 + 08, observed with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) are analysed. Thanks to the extremely high sensitivity of FAST, it is found that the radiation of PSR B0950 + 08 can be detected over the entire pulse period. To investigate the radiative characteristics of the pulsar’s ‘bridge emission’, a function, Θ(n), is defined to reveal the weak radiation there. It is suggested that the narrow peaks of both the main pulses and interpulses could be radiated at low altitude, while other weak emission (e.g. the ‘bridges’) comes from the upper magnetosphere, though its radiative mechanism is still a matter of debate. The measured mean pulse behaviours are consistent with previous results in the phase of strong emission of this pulsar, and both the frequency-independent separation between the interpulse and main pulse and the narrow pulse width may support a double-pole model. In order to understand the magnetospheric geometry of this pulsar, further polarization-calibrated observation with FAST and a proper determination of the baseline emission, especially during the weak emission phase, are surely required.