Detection of 107 glitches in 36 southern pulsars

By M. Yu, R. Manchester, G. Hobbs, Simon Johnston, V. Kaspi, Michael J. Keith, Andrew G. Lyne, G. Qiao, V. Ravi, J. Sarkissian and 2 more. 2012

163 citations recorded by the source corpus.

Timing observations from the Parkes 64-m radio telescope for 165 pulsarsbetween 1990 and 2011 have been searched for period glitches. Data spansfor each pulsar ranged between 5.3 and 20.8 yr. From the total of 1911yr of pulsar rotational history, 107 glitches were identified in 36pulsars. Out of these glitches, 61 have previously been reported whereas46 are new discoveries. Glitch parameters, both for the previously knownand the new glitch detections, were measured by fitting the timingresidual data. Observed relative glitch sizes{$\Delta$}{$\nu$}$_{g}$/{$\nu$} range between 10$^{-10}$ and10$^{-5}$, where {$\nu$} = 1/P is the pulse frequency. We confirmthat the distribution of {$\Delta$}{$\nu$}$_{g}$/{$\nu$} is bimodal withpeaks at approximately 10$^{-9}$ and 10$^{-6}$. Glitches aremostly observed in pulsars with characteristic ages between10$^{3}$ and 10$^{5}$ yr, with large glitches mostlyoccurring in the younger pulsars. Exponential post-glitch recoverieswere observed for 27 large glitches in 18 pulsars. The fraction Q of theglitch that recovers exponentially also has a bimodal distribution.Large glitches generally have low Q, typically just a few per cent, butlarge Q values are observed in both large and small glitches. Observedtime constants for exponential recoveries ranged between 10 and 300 dwith some tendency for longer time-scales in older pulsars. Shortertime-scale recoveries may exist but were not revealed by our data whichtypically have observation intervals of 2-4 weeks. For most of the 36pulsars with observed glitches, there is a persistent linear increase indot$\{${$\nu$} $\}$ (i.e. decrease in the slow-down rate |dot$\{${$\nu$} $\}$|) in theinterglitch interval. Where an exponential recovery is also observed,the effects of this are superimposed on the linear increase in dot$\{${$\nu$}$\}$. In some but not all cases, the slope of the linear recovery changesat the time of a glitch. The ddot$\{${$\nu$} $\}$ values characterizing thelinear changes in dot$\{${$\nu$} $\}$ are almost always positive and, aftersubtracting the magnetospheric component of the braking, areapproximately proportional to the ratio of |dot$\{${$\nu$} $\}$| and theinterglitch interval, as predicted by vortex-creep models.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Oceanography

View Paper: https://www.semanticscholar.org/paper/682a2e3c1808974d8a20b43ba1e35a55e0d5cc71