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arXiv · 2408.09204

A Series of (Net) Spin-down Glitches in PSR J1522-5735: Insights from the Vortex Creep and Vortex Bending Models

S. Q. Zhou·W. T. Ye·M. Y. Ge·E. GügercinoğLu·S. J. Zheng·C. Yu·J. P. Yuan·J. Zhang
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Abstract

Through a detailed timing analysis of $\textit{Fermi}$-LAT data, the rotational behavior of the $\gamma$-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 $|\Delta\nu_{\rm g}/\nu| \sim 10^{-8}$, 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.

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S. Q. Zhou, W. T. Ye, M. Y. Ge, E. GügercinoğLu, S. J. Zheng, C. Yu, J. P. Yuan, J. Zhang. 2024-08-17. A Series of (Net) Spin-down Glitches in PSR J1522-5735: Insights from the Vortex Creep and Vortex Bending Models. https://arxiv.org/abs/2408.09204

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