{
  "bibcode": "2020GCN.27012....1U",
  "body": "T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),\nJ. R. Cummings (CPI), P. A. Evans (U Leicester),\nH. A. Krimm (NSF), S. Laha (GSFC/UMBC),\nA. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),\nD. M. Palmer (LANL), T. Sakamoto (AGU),\nM. Stamatikos (OSU) (i.e. the Swift-BAT team):\n\nUsing the data set from T-239 to T+1361 sec from the recent telemetry\ndownlink,\nwe report further analysis of BAT GRB 200205B (trigger #954519 and #954520)\n(Evans et al., GCN Circ. 26993). We have combined the data from two\ntriggers (#954519 and #954520) for the analysis. All the times in this\ncircular\nare relative to the trigger time from #954519.\n\nThe BAT ground-calculated position is\nRA, Dec = 107.760, -56.488 deg which is\n   RA(J2000)  =  07h 11m 02.3s\n   Dec(J2000) = -56d 29' 18.1\"\nwith an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 47%.\n\nThe mask-weighted light curve shows several pulses that start from\n~T+20 s and end at ~T+550 s. The first prominent pulse occurs at ~T+60 s,\nfollowed by another significant structure with several overlapping pulses\nfrom ~T+380 s to ~T+520 s. There is a data gap from T+63 s to T+160 s,\nlikely due to problems of saving data because of the double triggers.\nT90 (15-350 keV) is 458.0 +- 5.4 sec (estimated error including\nsystematics).\n\nBecause of the data gap for part of the first pulse, we performed\nthe time-averaged spectrum for the interval of the second multi-pulse\nstructure\nfrom T+387.008 to T+520.396 sec. This interval is best fit by a power law\nwith\nan exponential cutoff. This fit gives a photon index 1.36 +- 0.22,\nand Epeak of 65.6 +- 10.8 keV (chi squared 41.92 for 56 d.o.f.).  For this\nmodel the total fluence in the 15-150 keV band is 5.4 +- 0.2 x 10^-6 erg/cm2\nand the 1-sec peak flux measured from T+438 sec in the 15-150 keV band is\n2.0 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index\nof 1.84 +- 0.05 (chi squared 58.00 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/954519/BA/",
  "circularId": 27012,
  "createdOn": 1581127416000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "GRB 200205B: Swift-BAT refined analysis",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "GRB 200205B"
}