{
  "bibcode": "2001GCN..1060....1F",
  "body": "X-ray precursors to the large flare from SGR 1900+14\n\nM. Feroci (IAS/CNR, Rome), J.J.M. in 't Zand (Astronomical Institute,\nUtrecht University and SRON), P. Soffitta (IAS/CNR, Rome), K. Hurley\n(UCB, California), F. Frontera (Univ. Ferrara and TESRE/CNR, Bologna)\nand E. Mazets (IOFFE, S. Petersburg), report:\n\n\"A high-time resolution analysis has been performed of the BeppoSAX\nWide Field Camera data of SGR 1900+14 taken on April 18, 2001, when\nthe most recent giant flare was detected (Guidorzi et al., GCN 1041\nand IAUC 7611). The data cover a short intermediate pointing of Wide\nField Camera unit 1 between two scheduled targets. The observation\nstarted 2780 s before the giant flare and ended with the automatic\nswitch off due to that flare. The observation was interrupted when\nBeppoSAX traversed the SAA, from 2282 till 1052 s before the\ngiant flare. The analysis revealed the presence of 3 short X-ray\nprecursors, occurring 2537, 755, and 444 s before the giant flare\n(respectively, 25975, 27757 and 28068 s UT), with durations of 100,\n125 and 55 ms, peak fluxes in excess of 20 Crab units (2-28 keV),\nand 9-28/2-9 keV spectral hardness ratios that are consistent with\npower laws with photon indices between roughly 0.5 and 1.2. None of the\nprecursors was detected in the gamma-ray data from the BeppoSAX/GRBM,\nthe gamma-ray burst detector on Ulysses, and from Konus on Wind.\"",
  "circularId": 1060,
  "createdOn": 988997172000,
  "email": "feroci@ias.rm.cnr.it",
  "subject": "X-ray precursors to the large flare from SGR 1900+14",
  "submitter": "Marco Feroci at IAS/CNR Frascati  <feroci@ias.rm.cnr.it>"
}