{
  "bibcode": "2017GCN.21384....1U",
  "body": "T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),\nS. B. Cenko (GSFC), J. R. Cummings (CPI),\nH. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),\nC. B. Markwardt (GSFC), D. M. Palmer (LANL),\nT. Sakamoto (AGU), M. Stamatikos (OSU),\n(i.e. the Swift-BAT team):\n\nUsing the data set from T-240 to T+962 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 170728B (trigger #765130)\n(Cenko et al., GCN Circ. 21371).  The BAT ground-calculated position is\nRA, Dec = 238.019, 70.111 deg which is\n  RA(J2000)  =  15h 52m 04.5s\n  Dec(J2000) = +70d 06' 40.0\"\nwith an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 5%.\n\nThe mask-weighted light curve shows a short multi-peaked structure from\n~T-0.1 s to ~T+0.7 s, followed by some weak emission till ~T+50 s,\nFermi/GBM also reports emission till ~T+47 s (Stanbro et al., GCN Circ. 21383).\nT90 (15-350 keV) is 47.7 +- 25.2 sec (estimated error including systematics).\n\nThe time-averaged spectrum for the short pulse from T-0.1 to T+0.7 sec is\nbest fit by a power law with an exponential cutoff.  This fit gives a photon\nindex -1.10 +- 1.71, and Epeak of 82.0 +- 24.2 keV (chi squared 51.71 for\n56 d.o.f.).  For this model the total fluence in the 15-150 keV band is\n6.2 +- 1.1 x 10^-7 erg/cm2. A fit to a simple power law gives a photon index\nof 1.21 +- 0.24 (chi squared 61.25 for 57 d.o.f.).\n\nThe time-averaged spectrum for the extended emission from T+0.7 to T+50.6 sec is\nbest fit by a simple power-law model.  The power law index of the time-averaged\nspectrum is 2.25 +- 0.57.  The fluence in the 15-150 keV band is\n9.8 +- 3.9 x 10^-7 erg/cm2.\n\nAll the quoted errors are at the 90% confidence level.\n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/765130/BA/",
  "circularId": 21384,
  "createdOn": 1501355082000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "GRB 170728B, Swift-BAT refined analysis",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "GRB 170728B"
}