{
  "bibcode": "2015GCN.18200....1G",
  "body": "S. Golenetskii, R. Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,\nM. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova,\nand T. Cline on behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 150821A (Swift-BAT trigger #652847:\nTroja et al., GCN 18186; Stamatikos et al., GCN 18196;\nFermi GBM detection: Roberts, GCN 18190)\ntriggered Konus-Wind at T0=35074.166 s UT (09:44:34.166).\n\nThe burst light curve shows a single multi-peaked pulse\nwhich started at ~T0-1.4 s and had a total duration of ~161.6 s.\nThe emission is seen up to ~10 MeV.\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 9.16(-2.22,+2.38)x10^-5 erg/cm2,\nand a 64-ms peak flux, measured from T0+4.768 s,\nof 3.68(-1.02,+1.27)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+164.096 s)\nis best fit in the 20 keV - 18 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -1.47 (-0.09,+0.15),\nthe high energy photon index beta = -2.21 (-7.79,+0.29),\nthe peak energy 350 (-125,+202) keV\n(chi2 = 129/97 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 - 18 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -1.07 (-0.10,+0.15),\nthe high energy photon index beta = -3.13 (-6.87,+0.80),\nthe peak energy 327 (-66,+58) keV\n(chi2 = 91/91 dof)\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB150821_T35074/\nThe background variations in the soft KW band are due to solar activity.\n\nAssuming the redshift z=0.755 (D'Elia et al., GCN 18187)\nand a standard cosmology model with H_0 = 70 km/s/Mpc,\nOmega_M = 0.27, and Omega_Lambda = 0.73,\nwe estimate the following rest-frame parameters:\nthe isotropic energy release E_iso is ~1.4x10^53 erg,\nthe peak luminosity L_iso is ~1.0x10^52 erg/s,\nand the rest-frame peak energy of the time-integrated spectrum,\nEp,i, is ~614 keV.\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 18200,
  "createdOn": 1440430369000,
  "email": "ann_kozlova@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 150821A",
  "submitter": "Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>",
  "eventId": "GRB 150821A"
}