{
  "bibcode": "2020GCN.29084....1F",
  "body": "D. Frederiks, S. Golenetskii, R.Aptekar, A.Lysenko,\nA. Ridnaia, D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long GRB 201216C (Swift detection:  Beardmore et al., GCN 29061;\nFermi GBM detection:  Malacaria et al., GCN 29071;\nAstroSat CZTI detection:  Nadella et al., GCN 29074;\nMAGIC detection:  Blanch et al., GCN 29075)\ntriggered Konus-Wind (KW) at T0=83248.844 s UT (23:07:28.844).\n\nThe burst light curve shows a multi-peaked structure with the total duration of ~40 s.\nThe emission is seen up to ~10 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB201216_T83248/\n\nAs observed by Konus-Wind, the burst had\na fluence of (1.86 �� 0.10)x10^-4 erg/cm^2 and\na 64-ms peak energy flux, measured from T0+24.704,\nof (1.82 �� 0.12)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+24.832 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 = -1.09 (-0.05,+0.06),\nthe high energy photon index beta = -2.32 (-0.13,+0.10),\nthe peak energy Ep = 333 (-28,+29) keV,\nchi2 = 102/97 dof.\n\nThe spectrum near the peak count rate (measured from T0+18.944\nto T0+26.368 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 = -0.99 (-0.05,+0.06),\nthe high energy photon index beta = -2.24 (-0.14,+0.10),\nthe peak energy Ep = 326 (-41,+47) keV,\nchi2 = 121/97 dof.\n\nAssuming the redshift z=1.1 (Vielfaure et al., GCN 29077)\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 following rest-frame parameters:\nthe isotropic energy release E_iso = (6.2 �� 0.6)x10^53 erg,\nthe peak luminosity L_iso = (1.3 �� 0.1)x10^53 erg/s,\nand the rest-frame peak energy of the time-integrated spectrum Ep,z=(700 �� 61) keV.\nWith these values, GRB 201216C is within 68% prediction bands\nfor both 'Amati' and 'Yonetoku' relations built for the sample\nof long KW GRBs with known redshifts (part I: Tsvetkova et al., ApJ 850 161, 2017;\npart II: Tsvetkova et al., ApJ, submitted),\nsee http://www.ioffe.ru/LEA/GRBs/GRB201216_T83248/GRB201216C.pdf\n\n\nAll the quoted errors are estimated at the 90% confidence level.\nAll the presented results are preliminary.",
  "circularId": 29084,
  "createdOn": 1608303032000,
  "email": "fred@mail.ioffe.ru",
  "subject": "Konus-Wind detection of GRB 201216C",
  "submitter": "Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>",
  "eventId": "GRB 201216C"
}