{
  "bibcode": "2021GCN.30366....1F",
  "body": "D. Frederiks, S. Golenetskii, A.Lysenko, A. Ridnaia,\nD. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long GRB 210702A (Swift detection: Lien et al., GCN 30351;\nCALET GRBM detection: Yamaoka et al., GCN 30362;\nAGILE detection: Ursi et al., GCN 30363)\ntriggered Konus-Wind (KW) at T0=68826.870 s UT (19:07:06.870).\n\nThe burst light curve shows a bright, FRED-like pulse\nwhich starts at ~T0-4 s, and has a total duration of ~90 s.\nThe emission is seen up to ~15 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB210702_T68826/\n\nAs observed by Konus-Wind, the burst had\na fluence of (2.5 �� 0.2)x10^-4 erg/cm^2 and\na 64-ms peak energy flux, measured from T0 + 7.808 s,\nof (3.0 �� 0.2)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).\n\nThe time-integrated spectrum (measured from T0 to T0+86.784 s)\nis best fit in the 20 keV - 20 MeV range\nby the GRB (Band) function with the following model parameters:\nthe low-energy photon index alpha = -0.91 (-0.09,+0.10),\nthe high energy photon index beta = -1.91 (-0.10,+0.08),\nthe peak energy Ep = 376 (-61,+63) keV,\nchi2 = 107/97 dof.\n\nThe spectrum near the peak count rate (measured from T0+4.096\nto T0+7.936 s) is 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 = -0.78 (-0.09,+0.11),\nthe high energy photon index beta = -2.00 (-0.09,+0.08),\nthe peak energy Ep = 402 (-64,+66) keV,\nchi2 = 111/92 dof.\n\nAssuming the redshift z=1.160 (Xu et al., GCN 30357)\nand a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,\nand Omega_Lambda = 0.685 (Planck Collaboration, 2014),\nwe estimate the isotropic energy release E_iso to ~9.3x10^53 erg,\nthe isotropic luminosity L_iso to ~2.4x10^53 erg/s,\nthe rest-frame peak energy of the time-integrated spectrum Epi,z to ~812 keV,\nand the rest-frame peak energy of the 'peak' spectrum Epp,z to ~870 keV.\nWith these values, GRB 210702A is within 68% prediction bands\nfor both 'Amati' and 'Yonetoku' relations for the sample of >300 long KW GRBs\nwith known redshifts (Tsvetkova et al., 2021, ApJ, 908, 83),\nsee http://www.ioffe.ru/LEA/GRBs/GRB210702_T68826/GRB210702A_rest_frame.pdf\n\nAll the quoted errors are estimated at the 90% confidence level.\nAll the presented results are preliminary.",
  "circularId": 30366,
  "createdOn": 1625316716000,
  "email": "fred@mail.ioffe.ru",
  "subject": "Konus-Wind detection of GRB 210702A",
  "submitter": "Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>",
  "eventId": "GRB 210702A"
}