Pulsars are rapidly rotating and highly magnetized neutron stars. They are taken as the most stable ‘clocks’ in the universe because their stable rotation. However, pulsar timing observations are also dominated by two categories of irregularities, ‘glitch’ and timing noise.

Pulsar glitch is a discontinuous and abrupt change in rotation speed, characterized by a sudden increase in spin frequency, and is often followed by a recovery process. It is generally regarded as having an internal origin, caused either by crust quake or by a sudden transfer of angular momentum from the crustal superfluid to the rest of the star.

Pulsar timing observations at Xinjiang Astronomical Observatory (XAO) are carried out with the 25-m telescope at Nanshan. There was a small jump in  resulting from a glitch around MJD 52950, the corresponding glitch size was      ~7.7(8)×10,-. However, the associated change in spin-down rate is relatively large: 0.067(8). It is worth notin that increased persistently over 800 d after the glitch, which was opposite to the typical post-glitch behavior. The average of post-glitch was about 9.6 percent larger than that pre-glitch.

In addition to the spin-down state change, emission mode switching was also found in the post-glitch data. The pulse profile became narrower and the pulsar began to switch between two states after the glitch (dashed line). Visually, the number of narrow pulse profiles was greater than that of wide ones.

Glitches are usually believed to have an internal origin. Further- more, the spin-down and emission behavior is thought to be driven by the external braking torque and magnetospheric radiation. Observations of PSR B2035+36 indicate that there should be connection between magnetospheric behavior and glitch activity. We discuss one possibility of magnetospheric fluctuation triggered by glitch event.

This work has been published by MNRAS. （MNRAS-L,478,L24）

Article link: https://doi.org/10.1093/mnrasl/sly068