{
  "bibcode": "2015GCN.17776....1C",
  "body": "J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), \nN. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), \nC. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), \nT. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): \n\nUsing the data set from T-239 to T+963 sec from the recent telemetry downlink, \nwe report further analysis of BAT GRB 150428B (trigger #639278) \n(Page, et al., GCN Circ. 17766).   The BAT ground-calculated position is \nRA, Dec = 292.661, 4.114 deg which is \n RA(J2000)  =  19h 30m 38.8s \n Dec(J2000) = +04d 06' 52.2��� \nwith an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).  \nThe partial coding was 40%. \n\nThe mask-weighted light curve shows three peaks.  The first peak starts at T-40 sec, \npeaks at T-25 sec and ends at T-20 sec.  The second peak starts at T-15 sec, peaks \nat T+5 sec and ends at T+50 sec.  And the third peak starts at T+55 sec, peaks at T+65 sec \nand ends at T+120 sec.  T90 (15-350 keV) is 130.9 +- 15.6 sec \n(estimated error including systematics).  \n\nThe time-averaged spectrum from T-40.1 to T+121.7 sec is best fit by a power law \nwith an exponential cutoff.  This fit gives a photon index 1.0 +- 0.5, and Epeak \nof 55 +- 10 keV (chi squared 37.44 for 56 d.o.f.).  For this model the total \nfluence in the 15-150 keV band is 3.7 +- 0.3 x 10^-6 erg/cm2 and the 1-sec peak flux \nmeasured from T+1.36 sec in the 15-150 keV band is 1.5 +- 0.3 ph/cm2/sec.  A fit \nto a simple power law gives a photon index of 1.87 +- 0.10 \n(chi squared 49.44 for 57 d.o.f.).  All 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/639278/BA/",
  "circularId": 17776,
  "createdOn": 1430228743000,
  "email": "tsakamoto@phys.aoyama.ac.jp",
  "subject": "GRB 150428B: Swift-BAT refined analysis",
  "submitter": "Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>",
  "eventId": "GRB 150428B"
}