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تسجيل مستخدم جديدGlitch or Anti-Glitch: a Bayesian View
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The sudden spin-down in the rotation of magnetar 1E 2259+586 observed by Archibald et al. (2013) was a rare event. However this particular event, referred to as an anti-glitch, was followed by another event which Archibald et al. (2013) suggested could either be a conventional glitch or another anti-glitch. Although there is no accompanied radiation activity or pulse profile change, there is decisive evidence for the existence of the second timing event, judging from the timing data. We apply Bayesian Model Selection to quantitatively determine which of these possibilities better explains the observed data. We show that the observed data strongly supports the presence of two successive anti-glitches with a Bayes Factor, often called the odds ratio, greater than 40. Furthermore, we show that the second anti-gtlich has an associated frequency change $Delta u$ of $-8.2 times 10^{-8}$ Hz. We discuss the implications of these results for possible physical mechanisms behind this anti-glitch.
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We suggest that the collision of a small solid body with a pulsar can lead to an observable glitch/anti-glitch. The glitch amplitude depends on the mass of the small body and the impact parameter as well. In the collision, a considerable amount of po
tential energy will be released either in the form of a short hard X-ray burst or as a relatively long-lasting soft X-ray afterglow. The connection between the glitch amplitude and the X-ray energetics can help to diagnose the nature of these timing anomalies.
We report on the timing and spectral properties of the soft X-ray emission from the magnetar 1E 2259+586 from January 2013, $sim 8$ months after the detection of an anti-glitch, until September 2019, using the Neil Gehrels Swift and NICER observatori
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