The spectacular X-ray echo of a magnetar burst
  The Anomalous X-ray Pulsar (AXP) 1E 1547.0-5408 reactivated in 2009 January
with the emission of dozens of short bursts. Follow-up observations with
Swift/XRT and XMM-Newton showed the presence of multiple expanding rings around
the position of the AXP. These rings are due to scattering, by different layers
of interstellar dust, of a very high fluence burst emitted by 1E 1547.0-5408 on
2009 January 22. Thanks to the exceptional brightness of the X-ray rings, we
could carry out a detailed study of their spatial and spectral time evolution
until 2009 February 4. This analysis gives the possibility to estimate the
distance of 1E 1547.0-5408. We also derived constraints on the properties of
the dust and of the burst responsible for this rare phenomenon.
