{
  "bibcode": "2018GCN.23061....1F",
  "body": "D. Frederiks, S. Golenetskii, R.Aptekar, A. Kozlova,\nA.Lysenko,  D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long, very bright GRB 180728A\n(Swift-BAT detection: Starling et al., GCN 23046;\nFermi-GBM detection: Veres et al., GCN 23053)\ntriggered Konus-Wind (KW) at T0=62954.093 s UT (17:29:14.093).\n\nThe burst light curve shows a smooth pulse with a total duration\n(T100) of ~17 s. The emission is seen up to ~10 MeV.\n\nAs observed by Konus-Wind, the burst had a fluence of\n(5.14 �� 0.29)x10^-5 erg/cm2 and a 64-ms peak energy flux,\nmeasured from T0+15.168, of (1.94 �� 0.15)x10^-5 erg/cm2\n(both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum (measured from T0 to T0+19.2 s)\nis best fit in the 30 keV - 15 MeV range\nby the GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -1.48 (-0.10,+0.12),\nthe high energy photon index beta = -2.57 (-0.18,+0.12),\nthe peak energy Ep = 97 (-6,+7) keV,\nchi2 = 94/96 dof.\n\nThe spectrum near the peak count rate (measured from T0+1.280 s\nto T0+1.792 s) is best fit in the 20 keV - 15 MeV range\nby the GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -1.44 (-0.15,+0.15),\nthe high energy photon index beta = -2.81 (-1.44,+0.24),\nthe peak energy Ep = 127 (-13,+18) keV,\nchi2 = 54/56 dof.\n\nAssuming the redshift z=0.117 (Rossi et al., GCN 23055)\nand a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,\nand Omega_Lambda = 0.685 (Planck Collaboration, 2014),\nwe estimate the following rest-frame parameters:\nthe isotropic energy release E_iso is (2.33 �� 0.10)x10^51 erg,\nthe peak luminosity L_iso is (9.51 �� 0.58)x10^50 erg/s\n(both in the 1-10000 keV rest-frame band).\nThe rest-frame peak energy of the time-integrated spectrum,\nEpi,z, is 108(-7, 8) keV, and the rest-frame peak energy of\nthe 'peak' spectrum, Epp,z, is 142(-15, 20) keV.\nWith these energetics, the burst lies on the upper\nedges of 68% prediction bands for both 'Amati' and 'Yonetoku'\nrelations built for the sample of 138 long KW GRBs with known\nredshifts (Tsvetkova et al., ApJ 850 161, 2017).\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB180728_T62954/\n\nAll the quoted errors are estimated at the 90% confidence level.\nAll the presented results are preliminary.",
  "circularId": 23061,
  "createdOn": 1532953263000,
  "email": "fred@mail.ioffe.ru",
  "subject": "Konus-Wind observation of the bright nearby GRB 180728A",
  "submitter": "Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>",
  "eventId": "GRB 180728A"
}