{
  "bibcode": "2009GCN..9204....1P",
  "body": "D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),\nJ. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),\nH. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), A. M. Parsons (GSFC),\nT. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),\nJ. Tueller (GSFC), T. N. Ukwatta (GWU)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-60 to T+243 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 090423 (trigger #350184)\n(Krimm, et al., GCN Circ. 9198).  The BAT ground-calculated position is\nRA, Dec = 148.891, 18.165 deg, which is \n   RA(J2000)  =  09h 55m 33.8s \n   Dec(J2000) = +18d 09' 55.7\" \nwith an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 92%.\n \nThe mask-weighted light curve shows a couple overlapping peaks starting\nat ~T-2 sec, peaking at T+4 sec, and ending at ~T+15 sec.\nT90 (15-350 keV) is 10.3 +- 1.1 sec (estimated error including systematics).\n \nThe time-averaged spectrum from T-0.7 to T+11.7 sec is best fit by a power law\nwith an exponential cutoff.  This fit gives a photon index 0.80 +- 0.50, \nand Epeak of 48.6 +- 6.2 keV (chi squared 41.4 for 56 d.o.f.).  For this\nmodel the total fluence in the 15-150 keV band is 5.9 +- 0.4 x 10^-7 erg/cm2\nand the 1-sec peak flux measured from T+3.50 sec in the 15-150 keV band is\n1.7 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index\nof 1.90 +- 0.10 (chi squared 59.9 for 57 d.o.f.).  All the quoted errors\nare at the 90% confidence level. \n \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/350184/BA/",
  "circularId": 9204,
  "createdOn": 1240490750000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 090423: Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 090423"
}