Pulse frequency changes of 1E 2259+586 and the binary interpretation


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Baykal A. , Swank J.

ASTROPHYSICAL JOURNAL, vol.460, no.1, pp.470-477, 1996 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 460 Issue: 1
  • Publication Date: 1996
  • Doi Number: 10.1086/176985
  • Title of Journal : ASTROPHYSICAL JOURNAL
  • Page Numbers: pp.470-477
  • Keywords: binaries, close, pulsars, individual (1E 2259+586), X-rays, stars, X-RAY PULSAR, SUPERNOVA REMNANT G109.1-1.0, NEUTRON-STARS, TIMING OBSERVATIONS, ACCRETION DISK, NOISE, 1E2259+586, EVOLUTION, MODEL, EXTRAORDINARY

Abstract

Pulse frequencies from the archival ROSAT observations of 1E 2259+586 are presented. A short-term spin-up episode superposed on the secular spin-down trend is observed. Combining the previously published pulse frequencies, we estimate the variance of the angular velocity over a 15 yr span of observations. The level of fluctuations in angular velocity is similar to that of established accreting binary neutron stars. These results favor accretion by a neutron star from a very low mass companion as the source of the X-ray luminosity, although accretion by a solitary neutron star from a residual disk might be possible.