{
  "bibcode": "2016GCN.20005....1T",
  "body": "A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,\nM. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline\non behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 161004B (Swift-BAT trigger #715246:\nD'Ai et al., GCN 19987; Sakamoto et al., GCN 19995;\nFermi GBM detection: Hamburg & Meegan, GCN 19998;\nCALET Gamma-Ray Burst Monitor detection: Yamada et al., GCN 20003)\ntriggered Konus-Wind at T0=83274.317 s UT (23:07:54.317).\n\nThe burst light curve shows a single pulse with a total duration of ~18 s.\nThe emission is seen up to ~2 MeV.\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 1.71(-0.07,+0.08)x10^-5 erg/cm2,\nand a 64-ms peak energy flux, measured from T0+4.144 s,\nof 3.43(-0.80,+0.80)x10^-6 erg/cm2/s\n(both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum of the burst\n(measured from T0 to T0+15.616 s)\nis best fit in the 20 keV - 2 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -1.05(-0.09,+0.09),\nand Ep = 175(-12,+14) keV (chi2 = 56/58 dof).\nFitting by the GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index:\nbeta < -3.14 (chi2 = 56/57 dof).\n\nThe spectrum near the peak count rate\n(measured from T0 to T0+7.424 s)\nis best fit in the 20 keV - 2 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -0.71(-0.10,+0.11),\nand Ep = 210(-13,+15) keV (chi2 = 67/58 dof).\nFitting by the GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index:\nbeta < -3.12 (chi2 = 67/57 dof).\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB161004_T83274/\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 20005,
  "createdOn": 1475769766000,
  "email": "tsvetkova@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 161004B",
  "submitter": "Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>",
  "eventId": "GRB 161004B"
}