Glitch or Anti-Glitch: a Bayesian View

Abstract

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 $\Delta \nu$ of $-8.2\times 10^{-8}$ Hz. We discuss the implications of these results for possible physical mechanisms behind this anti-glitch.

4 pages, 2 figures, published in ApJ L

References in corpus (1)

• TEMPO2, a new pulsar timing package. I: Overview

Cited by in corpus (5)

• Models of Pulsar Glitches
• A glitch and an anti-glitch in the anomalous X-ray pulsar 1E 1841-045
• A radiatively-quiet glitch and anti-glitch in the magnetar 1E 2259+586
• A simple mechanism for the anti-glitch observed in magnetar 1E 2259+586
• Interpreting the AXP 1E 2259+586 antiglitch as a change in internal magnetization