Artist's impression of a magnetar
This illustration depicts a magnetar: a spinning neutron star, characterised by rotation periods between 2 and 10 seconds, occasional episodes of extremely enhanced emission, and intense, short bursts of X-rays and gamma rays; these highly energetic events are presumed to be powered by an intense magnetic field.
A new, comprehensive study of the magnetar 1E 1547.0-5408 (see Kuiper et al., 2012), using data from INTEGRAL, RXTE and Swift, revealed unusual behaviour - the creation of both pulsed and unpulsed luminous non-thermal X-ray emission after a star quake. This is consistent with a model (Beloborodov, 2009) in which a star quake twists magnetic field lines that are anchored to the star's surface. When these twisted lines unravel they release magnetic energy and produce the observed radiation.
In this illustration, the curves converging at the poles of the magnetar represent the dipolar magnetic field lines; the entangled lines inside the magnetar symbolise the internal magnetic field.