Magnetars

A highly magnetized neutron star with fields a thousand times stronger than those of radio pulsars. There are two sub-classes of magnetars, anomalous X-Ray pulsar (AXP)s and soft gamma repeater (SGR)s, that were thought for many years to be separate and unrelated objects. In fact SGRs and AXPs are both neutron stars possessing magnetic fields of unprecedented strength of 10^14 - 10^16 G, and that show both steady X-ray pulsations as well as soft gamma-ray bursts. Their inferred steady X-ray luminosities are about one hundred times higher than their spin-down luminosities, requiring a source of power well beyond the magnetic dipole spin-down that powers rotation-powered pulsar (RPP)s. New high-energy components discovered in the spectra of a number of AXPs and SGRs require non-thermal particle acceleration and look very similar to high-energy spectral components of young rotation-powered pulsars.