{
  "bibcode": "2018GCN.23291....1K",
  "body": "A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks,\nM. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko,\nand T. Cline on behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 180925A (Swift-BAT detection:\nGropp et al., GCN 23268; Ukwatta et al., GCN 23273;\nInsight-HXMT/HE observation: Luo et al., GCN 23275)\ntriggered Konus-Wind at T0=52650.967 s UT (14:37:30.967).\n\nThe burst light curve shows a multipeaked structure\nwhich starts at ~T0 and has a total duration of ~26 s.\nThe emission is seen up to ~6 MeV.\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 1.44(-0.23,+0.32)x10^-5 erg/cm2,\nand a 64-ms peak flux, measured from T0+5.088 s,\nof 4.99(-1.51,+1.66)x10^-6 erg/cm2/s\n(both in the 20 keV - 10 MeV energy range).\n\nThe time-averaged spectrum of the burst\n(measured from T0 to T0+24.832 s)\nis best fit in the 20 keV - 6 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -0.99(-0.17,+0.21)\nand Ep = 528(-135,+239) keV (chi2 = 77/76 dof).\nFitting by a GRB (Band) model yields alpha = -0.84(-0.33,+0.40),\nEp = 374(-139,+403) keV, and beta = -2.0(-8.0,+0.3)\n(chi2 = 77/75 dof).\n\nThe spectrum near the maximum count rate\n(measured from T0+0.256 to T0+8.448 s)\nis best fit in the 20 keV - 6 MeV range\nby a power law with exponential cutoff model\nwith  alpha = -0.85(-0.20,+0.23)\nand Ep = 544(-125,+200) keV (chi2 = 93/76 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -2.8\n(chi2 = 93/75 dof).\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB180925_T52650/\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 23291,
  "createdOn": 1538484583000,
  "email": "ann_kozlova@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 180925A",
  "submitter": "Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>",
  "eventId": "GRB 180925A"
}