{
  "bibcode": "2021GCN.30388....1R",
  "body": "A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,\nD. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline\non behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 210704A\n(BALROG localization: Kunzweiler et al., GCN 30369;\nAGILE/MCAL detection: Ursi et al., GCN 30372;\nFermi-LAT detection: Berretta et al., GCN 30375;\nAstroSat CZTI detection: Prasad et al., GCN 30378;\nFermi GBM detection: Malacaria & Meegan, GCN 30380)\ntriggered Konus-Wind at T0=70400.814 s UT (19:33:20.814).\n\nThe burst light curve shows a bright peak\nin the interval from ~T0 to ~T0+2 s followed by\na weaker pulse peaked at ~T0+4.5 s.\nThe emission is seen up to ~4 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB210704_T70400/\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 2.25(-0.12,+0.14)x10^-5 erg/cm2,\nand a 64-ms peak flux, measured from T0+0.528 s,\nof 3.31(-0.37,+0.39)x10^-5 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+1.536 s)\nis best fit in the 20 keV - 4 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.21(-0.09,+0.10),\nthe high energy photon index beta = -2.97(-0.31,+0.22),\nthe peak energy Ep = 271(-14,+14) keV\n(chi2 = 56/57 dof).\n\nThe spectrum near the maximum count rate\n(measured from T0+0.256 to T0+0.768 s)\nis best fit in the 20 keV - 4 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.20(-0.12,+0.13),\nthe high energy photon index beta = -2.84(-0.40,+0.25),\nthe peak energy Ep = 320(-24,+27) keV\n(chi2 = 44/53 dof).\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 30388,
  "createdOn": 1625565111000,
  "email": "ridnaia@mail.ioffe.ru",
  "subject": "Konus-Wind detection of GRB 210704A",
  "submitter": "Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>",
  "eventId": "GRB 210704A"
}