{
  "bibcode": "2019GCN.24784....1K",
  "body": "A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks,\nM. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline\non behalf of the Konus-Wind team, report:\n\nThe short-duration, very bright GRB 190606A\n(AGILE-MCAL detection: Ursi et al., GCN Circ. 24759;\nFermi-LAT detection: Bissaldi et al., GCN Circ. 24761;\nFermi-GBM detection: Roberts et al., GCN Circ. 24764;\nIPN triangulation: Kozlova et al., GCN 24765)\ntriggered Konus-Wind at T0=6903.8 s UT (01:55:03.800).\n\nThe burst light curve shows a single pulse\nwhich starts at ~T0 and has a total duration of ~0.2 s.\nThe emission is seen up to ~10 MeV.\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 1.16(-0.18,+0.18)x10^-5 erg/cm2,\nand a 16-ms peak flux, measured from T0+0.034 s,\nof 1.45(-0.39,+0.35)x10^-4 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+0.192 s)\nis best fit in the 20 keV - 10 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -1.13(-0.08,+0.09)\nand Ep = 2373(-665,+939) keV (chi2 = 56/54 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -1.8\n(chi2 = 55/53 dof).\n\nThe spectrum near the maximum count rate\n(measured from T0 to T0+0.064 s)\nis best fit in the 20 keV - 10 MeV range\nby a power law with exponential cutoff model:\nwith  alpha = -1.19(-0.10,+0.12)\nand Ep = 3194(-1324,+2736) keV (chi2 = 32/34 dof).\nFitting by a GRB (Band) model yields:\nthe low-energy photon index alpha = -0.88(-0.26,+0.45),\nthe high energy photon index beta = -1.67(-0.27,+0.15),\nthe peak energy Ep = 664(-388,+1038) keV\n(chi2 = 26/33 dof).\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB190606_T06903/\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 24784,
  "createdOn": 1560274151000,
  "email": "ann_kozlova@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 190606A",
  "submitter": "Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>",
  "eventId": "GRB 190606A"
}