English

\emph{RXTE} Timing Analysis of the AXP 1E 2259+586

High Energy Astrophysical Phenomena 2011-10-07 v2

Abstract

We report the pulse timing analysis of \emph{Rossi X-ray Timing Explorer} (\emph{RXTE}) observations of the anomalous X-ray pulsar 1E 2259+586 from its 2002 outburst to October, 2010. Our objectives are to extend the work on the recovery stage after the 2002 glitch, investigate the variations caused by the second glitch which occurred in 2007 and look for other unusual events, if any, that arise in the regular spin-down trend of the source. The recovery of the 2002 glitch gives good fit when the two-exponential glitch model of the Crab pulsar is used, rather than the standard glitch model, in the 1360-day interval after the first glitch. The sampling of the following 260-day is not frequent enough to be phase-connected. After that interval, our timing analysis yields that there is a fractional frequency change of Δνν8.20(2)×107\frac{\Delta\nu}{\nu}\sim8.20(2)\times10^{-7}. Moreover, we report two frequency shifts of fractional changes, Δνν3×108,1×108\frac{\Delta\nu}{\nu}\sim3\times10^{-8},-1\times10^{-8}: The first one at MJD 53750\sim53750 had a positive fractional frequency change in contrast to the second one at MJD 54880\sim54880 for which the pulse frequency decreased. These frequency shifts both resemble the microglitches observed in radio pulsars.

Keywords

Cite

@article{arxiv.1105.1630,
  title  = {\emph{RXTE} Timing Analysis of the AXP 1E 2259+586},
  author = {Burcin Icdem and Altan Baykal and S. Cagdas Inam},
  journal= {arXiv preprint arXiv:1105.1630},
  year   = {2011}
}

Comments

13 pages, 1 figure, accepted to be published in MNRAS