{
  "subject": "Konus-Wind detection of GRB 261010A",
  "circularId": 45925,
  "createdOn": 1791823684335,
  "submittedHow": "email",
  "eventId": "GRB 261010A",
  "body": "D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,\nA. Tsvetkova,  M. Ulanov, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 261010A (Swift detection:\nLien, et al., GCN 45889; Barthelmy et al., GCN 45918;\nFermi-GBM detection: The Fermi GBM team, GCN 45888;\nPalafox & Jameson, GCN 45911)\ntriggered Konus-Wind (KW) at T0=69424.522 s UT (19:17:04.522).\n\nThe KW triggered on a bright, hard-spectrum, multipeaked pulse,\nwith a duration of ~3 s, which is superimposed over a broad,\nless intense emission pulse that started ~10 s before the trigger,\npeaked at ~T0+16 s, and lasted for ~70 s.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB261010_T69424/\n\nAs observed by Konus-Wind, the burst had\na fluence of (1.72 ± 0.47)x10^-5 erg/cm^2 and\na 64-ms peak energy flux, measured from T0 + 0.128 s,\nof (6.02 ± 1.08)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).\n\nThe spectrum of the bright pulse (measured from T0 to T0+8.448 s)\nis best fitted in the 20 keV - 15 MeV range by a power law with exponential\ncutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith alpha = -0.98 (-0.12, + 0.15) and Ep = 837(-194,+299) keV, PGstat = 81/98 dof.\nFitting this spectrum by a Band GRB function yields the same values\nof alpha and Ep, and only an upper limit on the high energy photon\nindex beta of -2.0\n\nThe spectrum of the broad pulse (measured from T0+8.448 s to T0+49.408 s)\nis best fitted in the 20 keV - 15 MeV range by a simple PL function\nwith the PL index of 1.92 (-0.07,+0.08),\nPGstat = 103/99 dof.\n\nAll the quoted errors are estimated at the 68% confidence level.\nAll the presented results are preliminary.",
  "submitter": "Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>"
}