{
  "bibcode": "2013GCN.14368....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-duration GRB 130408A\n(Swift/BAT trigger=553132: Lien et al., GCN 14361)\ntriggered Konus-Wind at T0=78701.184s UT (21:51:41.194)\n\nThe light curve shows a bright pulse from ~T0-0.5 to ~T0+5 s\nfollowed by a much weaker emission pulse peaked around ~T0+12;\na total duration of the burst is ~15 s.\nThe emission is seen up to several MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB130408_T78701/\n\nAs observed by Konus-Wind, the burst\nhad a fluence of (1.2 � 0.2)x10-5 erg/cm2,\nand a 64-ms peak flux, measured from T0+3.328s,\nof (5.2 � 0.5)x10-6 erg/cm2/s\n(both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum (measured from T0 to T0+16.640 s)\nis 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 = -0.4 � 0.2,\nthe high energy photon index beta = -2.3 � 0.2,\nthe peak energy Ep = 211 � 29 keV,\nchi2 = 99.4/97 dof.\n\nThe spectrum at the maximum count rate (measured from T0 to T0+8.448 s)\nis 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 = -0.70 � 0.15,\nthe high energy photon index beta = -2.3 � 0.3,\nthe peak energy Ep = 272 � 40 keV,\nchi2 = 87.7/99 dof.\n\nAssuming redshift z=3.758 (Hjorth et al., GCN 14365; Tanvir et al., GCN 14366),\nand a standard cosmology (H_0=70 km/s/Mpc, Omega_M=0.3, Omega_\\Lambda=0.7),\nwe estimate the following cosmological rest-frame parameters of the prompt\ngamma-ray emission:\n- the isotropic equivalent energy release E_iso = (3.3 � 0.6)x10^53 erg;\n- the peak luminosity L_iso = (5.5 � 0.5)x10^53 erg/s;\n- the peak energy of the time-integrated spectrum Ep_rest = 1.00 � 0.14 MeV.\n\nAll the quoted results are preliminary.",
  "circularId": 14368,
  "createdOn": 1365500983000,
  "email": "fred@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 130408A",
  "submitter": "Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>",
  "eventId": "GRB 130408A"
}