{
  "bibcode": "2013GCN.14417....1G",
  "body": "S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,\nP. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf\nof the Konus-Wind team, report:\n\nThe long GRB 130418A (Swift-BAT trigger #553847:\nDe Pasquale et al., GCN 14377; Cummings et al., GCN 14392)\nwas observed by Konus-Wind (K-W) in the waiting mode.\n\nK-W light curve shows a soft pulse started ~215 s before\nthe BAT trigger (T0(BAT)=19:00:53).\nA total duration of the pulse is ~120 s.\nThe decay phase of the burst which had triggered Swift-BAT\nis virtually indistinguishable from the K-W background.\nSince the K-W ecliptic latitude response to the burst\nis consistent with the BAT localization, we suggest\nthe pulse observed by K-W is an initial phase of GRB 130418A.\n\nAs observed by Konus-Wind, this part of the burst had\na fluence of (1.57 � 0.25)x10^-5 erg/cm2 and a 3-s peak flux,\nmeasured from T0(BAT)-186 s, of (2.5 � 0.4)x10^-7 erg/cm2/s\n(both in the 20 - 1200 keV energy range).\n\nFitting the K-W 3-channel time-averaged spectrum\n(from T0(BAT)-215 s to T0(BAT)-95 s) by a simple\npower-law model yields a photon index of 2.12 � 0.09,\nwhich is consistent with the slope reported by BAT\nfor the burst tail.\n\nAssuming z=1.218 (de Ugarte Postigo et al., GCN 14380;\nKruehler et al. GCN 14390) and a standard cosmology model\nwith H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73,\nthe isotropic energy release E_iso is (6.3 � 1.0)x10^52 erg,\nand the peak luminosity (L_iso)_max is (1.2 � 0.2)x10^51 erg/s.\n\nAll the quoted errors are estimated at the 1 sigma confidence level.\n\nThe K-W light curve of this burst is available at\nhttp://www.ioffe.rssi.ru/LEA/GRBs/GRB130418A/",
  "circularId": 14417,
  "createdOn": 1366479753000,
  "email": "fred@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 130418A",
  "submitter": "Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>",
  "eventId": "GRB 130418A"
}