Key points are not available for this paper at this time.
Through a detailed timing analysis of Fermi-LAT data, the rotational behavior of the -ray pulsar PSR J1522-5735 was tracked from August 2008 (MJD 54692) to January 2024 (MJD 60320). During this 15. 4-year period, two over-recovery glitches and four anti-glitches were identified, marking a rare occurrence in rotation-powered pulsars (RPPs). The magnitudes of these (net) spin-down glitches were determined to be | ₆/| 10^-8, well above the estimated detectability limit. For the two over-recovery glitches, the respective recovery fractions Q are 2. 1 (7) and 1. 4 (2). Further analysis showed no substantial variations in either the flux or pulse profile shape in any of these events, suggesting that small (net) spin-down glitches, unlike large events observed in magnetars and magnetar-like RPPs, may occur without leaving an impact on the magnetosphere. Within the framework of the vortex creep and vortex bending models, anti-glitches and over-recoveries indicate the recoupling of vortex lines that moved inward as a result of a crustquake; meanwhile, the apparent fluctuations in the spin-down rate after the glitches occur as a result of the coupling of the oscillations of bent vortex lines to the magnetosphere.
Zhou et al. (Sat,) studied this question.