Investigation of nulling and subpulse drifting properties of PSR J1727?2739

摘要

Aims. We intend to study of the nulling and subpulse drifting in PSR J1727 ? 2739 in detail to investigate its radiation properties. Methods. The observations were carried out on 20 March, 2004 using the Parkes 64-m radio telescope with a central frequency of 1518 MHz. A total of 5568 single pulses were analysed. Results. This pulsar shows well-defined nulls with lengths lasting from 6 to 281 pulses and separated by burst phases ranging from 2 to 133 pulses. We estimate a nulling fraction of around 68%. No emission in the average pulse profile integrated over all null pulses is detected with significance above 3 σ . Most transitions from nulls to bursts are within a few pulses, whereas the transitions from bursts to nulls exhibit two patterns of decay; these transitions either decrease gradually or rapidly. In the burst phase, we find that there are two distinct subpulse drift modes with vertical spacing between the drift bands of 9.7 ± 1.6 and 5.2 ± 0.9 pulse periods, while sometimes there is a third mode with no subpulse drifting. Some mode transitions occur within a single burst, while others are separated by nulls. Different modes have different average pulse profiles. Possible physical mechanisms are discussed.