{
  "bibcode": "2013GCN.14554....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), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),\nT. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC),\nT. N. Ukwatta (MSU)\n  \nUsing the data set from T-61 to T+242 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 130504A (trigger #555096)\n(Cummings, et al., GCN Circ. 14551).  The BAT ground-calculated position is\nRA, Dec = 272.459, -16.320 deg which is\n    RA(J2000)  =  18h 09m 50.1s\n    Dec(J2000) = -16d 19' 13.1\"\nwith an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).  The\npartial coding was 100%.\n\nThis position is 5.3 arcmin away from the automated flight position reported\nin GCN circular# 14551.  The imaging interval selected onboard was not optimum.\nThe refined error circle includes the position of the XRT afterglow candidate\nreported by D'Avanzo et al. in GCN circular# 14553, hence we believe that\nfading x-ray source to be the correctly identified afterglow of GRB 130504A.\n\nThe mask-weighted light curve shows multiple weak peaks.  T90 (15-350 keV) is\n50 +- 10 sec (estimated error including systematics).\n  \nThe time-averaged spectrum from T-31.07 to T+36.84 sec is best fit by a power\nlaw with an exponential cutoff.  This fit gives a photon index 0.52 +- 0.68,\nand Epeak of 84.5 +- 47.6 keV (chi squared 82.16 for 56 d.o.f.).  For this\nmodel the total fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-06 erg/cm2\nand the 1-sec peak flux measured from T-0.06 sec in the 15-150 keV band is\n0.9 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index\nof 1.41 +- 0.15 (chi squared 88.43 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/555096/BA/",
  "circularId": 14554,
  "createdOn": 1367665702000,
  "email": "james.r.cummings@nasa.gov",
  "subject": "GRB 130504A, Swift-BAT refined analysis",
  "submitter": "Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>",
  "eventId": "GRB 130504A"
}