Recent glitches detected in the Crab pulsar

TL;DR

This study reports nine glitches in the Crab pulsar over a decade, highlighting their random occurrence, significant size variations, and associated changes in pulsar braking index, suggesting a link to particle wind variations.

Contribution

First comprehensive analysis of Crab pulsar glitches over ten years, revealing their random nature, size diversity, and impact on pulsar braking behavior, with comparisons to Vela pulsar glitches.

Findings

Nine glitches detected from 2000 to 2010.

Largest glitch observed with a 6.8e-6 Hz jump.

Glitch sizes vary over two orders of magnitude.

Abstract

From 2000 to 2010, monitoring of radio emission from the Crab pulsar at Xinjiang Observatory detected a total of nine glitches. The occurrence of glitches appears to be a random process as described by previous researches. A persistent change in pulse frequency and pulse frequency derivative after each glitch was found. There is no obvious correlation between glitch sizes and the time since last glitch. For these glitches $\Delta\nu_{p}$ and $\Delta\dot{\nu}_{p}$ span two orders of magnitude. The pulsar suffered the largest frequency jump ever seen on MJD 53067.1. The size of the glitch is $\sim$ 6.8 $\times 10^{-6}$ Hz, $\sim$ 3.5 times that of the glitch occured in 1989 glitch, with a very large permanent changes in frequency and pulse frequency derivative and followed by a decay with time constant $\sim$ 21 days. The braking index presents significant changes. We attribute this variation to a varying particle wind strength which may be caused by glitch activities. We discuss the properties of detected glitches in Crab pulsar and compare them with glitches in the Vela pulsar.