{
  "bibcode": "2022GCN.31429....1R",
  "body": "A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,\nA. Tsvetkova,  M. Ulanov, and T. Cline\non behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 220107A\n(Fermi/GBM trigger #663259536: Fermi GBM Team, GCN 31399;\nKunzweiler et al., GCN 31400; Veres and Meegan, GCN 31406;\nSwift/BAT-GUANO localization: DeLaunay et al., GCN 31402;\nAstroSat CZTI detection: Suresh et al., GCN 31408)\ntriggered Konus-Wind at T0=53142.427 s UT (14:45:42.427).\n\nThe burst light curve shows a multipeaked structure\nstarted at ~T0-7.6 s with a total duration of ~110.8 s.\nThe emission is seen up to ~2 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB220107_T53142/\n\nAs observed by Konus-Wind, the burst\nhad a fluence of 5.48(-0.30,+0.34)x10^-5 erg/cm2,\nand a 64-ms peak flux, measured from T0+81.344 s,\nof 8.18(-1.55,+1.54)x10^-6 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+105.984 s)\nis best fit in the 20 keV - 2 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -1.02(-0.11,+0.12)\nand Ep = 247(-24,+30) keV (chi2 = 53/61 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -2.4\n(chi2 = 53/60 dof).\n\nThe spectrum near the maximum count rate\n(measured from T0+73.984 to T0+89.600 s)\nis best fit in the 20 keV - 2 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.86(-0.11,+0.12),\nthe high energy photon index beta = -2.91(-1.53,+0.32),\nthe peak energy Ep = 186(-15,+17) keV\n(chi2 = 46/60 dof).\n\nAssuming the redshift z=1.246 (Castro-Tirado et al., GCN 31423)\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 (2.3 �� 0.1)x10^53 erg,\nthe isotropic luminosity L_iso to (7.8 �� 1.5)x10^52 erg/s,\nthe rest-frame peak energy of the time-integrated spectrum Epi,z to (555 ��\n67) keV,\nand the rest-frame peak energy of the 'peak' spectrum Epp,z to (418 �� 38)\nkeV.\nWith these values, GRB 220107A is within 68% prediction bands for\nfor both 'Amati' and 'Yonetoku' relations for the sample of >300 long KW\nGRBs\nwith known redshifts (Tsvetkova et al., 2021, ApJ, 908, 83),\nsee http://www.ioffe.ru/LEA/GRBs/GRB220107_T53142/GRB220107A_rest_frame.pdf\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 31429,
  "createdOn": 1641843670000,
  "email": "ridnaia@mail.ioffe.ru",
  "subject": "Konus-Wind detection of GRB 220107A",
  "submitter": "Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>",
  "eventId": "GRB 220107A"
}