Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars


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Castro-Tirado A. J., de Ugarte Postigo A., Gorosabel J., Jelinek M., Fatkhullin T. A., Sokolov V. V., ...More

NATURE, vol.455, no.7212, pp.506-509, 2008 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 455 Issue: 7212
  • Publication Date: 2008
  • Doi Number: 10.1038/nature07328
  • Journal Name: NATURE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.506-509
  • Çukurova University Affiliated: Yes

Abstract

Magnetars(1) are young neutron stars with very strong magnetic fields of the order of 10(14)-10(15) G. They are detected in our Galaxy either as soft gamma-ray repeaters or anomalous X-ray pulsars. Soft gamma-ray repeaters are a rare type of gamma-ray transient sources that are occasionally detected as bursters in the high-energy sky(2-4). No optical counterpart to the gamma-ray flares or the quiescent source has yet been identified. Here we report multi-wavelength observations of a puzzling source, SWIFT J195509+261406. We detected more than 40 flaring episodes in the optical band over a time span of three days, and a faint infrared flare 11 days later, after which the source returned to quiescence. Our radio observations confirm a Galactic nature and establish a lower distance limit of similar to 3.7 kpc. We suggest that SWIFT J195509+261406 could be an isolated magnetar whose bursting activity has been detected at optical wavelengths, and for which the long- term X- ray emission is short- lived. In this case, a new manifestation of magnetar activity has been recorded and we can consider SWIFT J195509+261406 to be a link between the 'persistent' soft gamma-ray repeaters/anomalous X- ray pulsars and dim isolated neutron stars.