X-ray bursts from the transient magnetar candidate XTE J810-197

Peter M. Woods, Chryssa Kouveliotou, Fotis P. Gavriil, Victoria M. Kaspi, Mallory S.E. Roberts, Alaa Ibrahim, Craig B. Markwardt, Jean H. Swank, Mark H. Finger

Research output: Contribution to journalArticle

Abstract

We have discovered four X-ray bursts, recorded with the Rossi X-ray Timing Explorer Proportional Counter Array between 2003 September and 2004 April, that we show to originate from the transient magnetar candidate XTE J1810-197. The burst morphologies consist of a short spike or multiple spikes lasting ∼ 1 s each, followed by extended tails of emission where the pulsed flux from XTE J1810-197 is significantly higher. The burst spikes are likely correlated with the pulse maxima, having a chance probability of a random phase distribution of 0.4%. The burst spectra are best fitted to a blackbody with temperatures 4-8 keV, considerably harder than the persistent X-ray emission. During the X-ray tails following these bursts, the temperature rapidly cools as the flux declines, maintaining a constant emitting radius after the initial burst peak. During the brightest X-ray tail, we detect a narrow emission line at 12.6 keV, with an equivalent width of 1.4 keV and a probability of chance occurrence of less than 4 × 10-6. The temporal and spectral characteristics of these bursts closely resemble the bursts seen from 1E 1048.1-5937 and a subset of the bursts detected from 1E 2259+586, thus establishing XTE J1810-197 as a magnetar candidate. The bursts detected from these three objects are sufficiently similar to one another, yet significantly different from those seen from soft gamma repeaters, that they likely represent a new class of bursts from magnetar candidates exclusive (thus far) to the anomalous X-ray pulsar-like sources.

Original languageEnglish (US)
Pages (from-to)985-997
Number of pages13
JournalAstrophysical Journal
Volume629
Issue number2 I
DOIs
StatePublished - Aug 20 2005

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Keywords

  • Pulsars: general
  • Stars: individual (XTE j1810-197)
  • X-rays: bursts

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Woods, P. M., Kouveliotou, C., Gavriil, F. P., Kaspi, V. M., Roberts, M. S. E., Ibrahim, A., Markwardt, C. B., Swank, J. H., & Finger, M. H. (2005). X-ray bursts from the transient magnetar candidate XTE J810-197. Astrophysical Journal, 629(2 I), 985-997. https://doi.org/10.1086/431476