{
  "bibcode": "2013GCN.15260....1G",
  "body": "S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin,\nP. Oleynik, M. Ulanov, D. Svinkin, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe very long GRB 130925A\n(Swift-BAT trigger #571830: Lien et al., GCN 15246;\nMarkwardt et al., GCN 15257;\nMAXI/GSC detection: Suzuki et al., GCN 15248;\nFermi/GBM detection: Fitzpatrick, GCN 15255;\nINTEGRAL/SPI-ACS observation: Savchenko et al., GCN 15259)\nwas detected by Konus-Wind in the waiting mode.\n\nThe light curve shows several multi-peaked pulses separated\nby long periods of a low-level emission with a total duration of ~4500 s.\nAt least three major emission episodes can be distingushed:\nthe first one, which triggered BAT, started at ~T0(BAT)-130 s\nand lasted until ~T0(BAT)+170 s; the second, more fluent episode,\nfrom ~T0(BAT)+1750 s to ~T0(BAT)+2950 s;\nand the third, the weakest one, which onset corresponds\nto the MAXI detection, from ~T0(BAT)+3730 s to ~T0(BAT)+4360 s.\n\nThe possible precursor detected by GBM is clearly seen\nat ~T0(BAT)-900 s in the softest KW energy band.\n\nAs observed by Konus-Wind, the burst had a fluence of\n(5.0 � 0.1)x10^-4 erg/cm2 and a 2.944-s peak energy flux,\nmeasured from T0(BAT)+2548.858, of (1.0 � 0.03)x10^-6 erg/cm2\n(both in the 20 - 10000 keV energy range).\n\nThe emission shows no signs of strong spectral variability.\nModeling the KW 3-channel time-integrated spectrum\n(from T0(BAT)-120 s to T0(BAT)+4340 s) by a power law\nwith exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nyields alpha = -1.42 � 0.04, and Ep = 181 � 10 keV.\n\nAssuming z = 0.347 (Vreeswijk et al., GCN 15249) and a\nstandard cosmology model with H_0 = 71 km/s/Mpc, Omega_M = 0.27,\nOmega_Lambda = 0.73,\nthe isotropic energy release E_iso = (1.50 � 0.03)x10^53 erg,\nthe peak isotropic luminosity L_iso = (4.0 � 0.1)x10^50 erg,\nand Ep_rest is 244 �  13 keV.\n\nThus, the prompt gamma-ray emission properties of this GRB: fluence, Ep,\nand E_iso are similar to those observed in other long energetic GRBs;\nthe only outstanding feature of the burst is its huge duration.\nIn that, it resembles other ultra-long bursts: GRB 111209A at z=0.677\n(with total duration of ~10000 s: Golenetskii et al., GCN 12663)\nand GRB 121027A at z=1.77 (with a total duration of >4000 s: Starling et al.,\nin preparation).\nTherefore, we suggest that the extremely rapid and dramatic X-ray flaring\nobserved over the first 10^4 s after the BAT trigger (Evans et al., GCN 15254)\nat least partially corresponds to the burst prompt emission.\n\nAll the quoted errors are estimated at the 1 sigma confidence level.\nAll the presented results are preliminary.\n\nThe K-W light curve of this burst is available at\nhttp://www.ioffe.rssi.ru/LEA/GRBs/GRB130925A/",
  "circularId": 15260,
  "createdOn": 1380209762000,
  "email": "fred@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 130925A",
  "submitter": "Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>",
  "eventId": "GRB 130925A"
}