Editor's Summary

29 May 2008

Magnetars: Ring of fire

Magnetars are rotating neutron stars with magnetic fields at least an order of magnitude stronger than those of 'normal' radio pulsars. There are only about a dozen magnetars known to date and their evolutionary history is not yet firmly established. Circumstantial evidence links them to very massive stars as progenitors; now the discovery of an infrared ring or shell around magnetar SGR 1900+14 (a soft gamma repeater) confirms that link. Observations from the Spitzer telescope are consistent with the presence of a dust-free cavity in the magnetar environment — possibly produced by the giant flare emitted by the source in August 1998 — strongly suggesting an association with a cluster of massive stars.

LetterAn infrared ring around the magnetar SGR 1900+14

S. Wachter, E. Ramirez-Ruiz, V. V. Dwarkadas, C. Kouveliotou, J. Granot, S. K. Patel & D. Figer