Wide-band X-ray Studies of Magnetars with Suzaku

摘要

From its launch in 2005, the Suzaku satellite has been observed 10 magnetars including 7 persistent objects and 3 activated ones. The hard-tail component was successfully detected from 7 of them, including two activated sources (SGR 0501+4516 and IE 1547.0-5408), together with the soft component from all of them. Unified spectral studies over the 0.8-70 keV range revealed a clear wide-band spectral evolution, in which the hard-tail component become weaker and harder towards sources with older characteristic age. Specifically, a tight correlation was found between the characteristic age and the hardness ratio between the two components. In addition, the photon index of the hard emission, ranging from ~1.7 to ~0.4, is negatively correlated to the characteristic age.