The effect of X-ray dust scattering on a bright burst from the magnetar 1E 1547.0-5408.

A bright burst, followed by an X-ray tail lasting ~10 ks, was detected during an XMM-Newton observation of the magnetar 1E 1547.0-5408 carried out on 2009 February 3. The burst, also observed by Swift/BAT, had a spectrum well fitted by the sum of two blackbodies with temperatures of ~4 and 10 keV and a fluence in the 0.3-150 keV energy range of ~10-5 erg cm-2. The X-ray tail had a fluence of ~4 x 10-8 erg cm-2. Thanks to the knowledge of the distances and relative optical depths of three dust clouds between us and 1E 1547.0-5408, we show that most of the X-rays in the tail can be explained by dust scattering of the burst emission, except for the first ~20-30 s. We point out that other X-ray tails observed after strong magnetar bursts may contain a non-negligible contribution due to dust scattering. [ABSTRACT FROM AUTHOR]