Sub-MeV band observation of a hard burst from AXP 1E 1547.0−5408 with the Suzaku Wide-band All-sky Monitor

The 2.1-s anomalous X-ray pulsar 1E 1547.0−5408 exhibited an X-ray outburst on 2009 January 22, emitting a large number of short bursts. The wide-band all-sky monitor (WAM) on-board Suzaku detected at least 254 bursts in the 0.16–6.2MeV band over the period of January 22 00:57–17:02 UTC from the direction of 1E 1547.0−5408. One of these bursts, which occurred at 06:45:13, produced the brightest fluence in