{
  "circularId": 45496,
  "eventId": "GRB 260829A",
  "submittedHow": "web",
  "format": "text/plain",
  "eventType": [
    "GRB",
    "Gamma-ray Transient"
  ],
  "createdOn": 1788347535153,
  "subject": "Konus-Wind detection of GRB 260829A",
  "body": "A. Ridnaia, D. Frederiks, A. Lysenko, V. Panteleeva,\nD. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long-duration GRB 260829A\n(Fermi-GBM detection: Fermi GBM team, GCN 45464;\nMalacaria et al., GCN 45467;\nBALROG localization: Preis & Greiner, GCN 45465;\nGECAM-B detection: Zao et al., GCN 45470;\nIPN triangulation: Kozyrev et al., GCN 45476;\nAstroSat CZTI detection: Goyal et al., GCN 45485;\nSVOM-GRM detection: Luo et al., GCN 45495)\ntriggered Konus-Wind at T0=22110.076 s UT (06:08:30.076).\n\nThe burst light curve shows an initial weak emission\nepisode starting at ~T0-21.3 s, followed by a brighter \nmulti-peaked structure. The total burst duration is ~34.8 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/GRB260829_T22110/\n\nAs observed by Konus-Wind, the burst\nhad the total fluence of 2.05(-0.09,+0.10)x10^-5 erg/cm2,\nand the 64-ms peak flux, measured from T0+2.208 s,\nof 8.44(-0.91,+0.92)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+16.640 s)\nis best fit in the 20 keV - 10 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith alpha = -0.94(-0.09,+0.09)\nand Ep = 330(-24,+28) keV (chi2 = 114/98 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -2.8\n(chi2 = 114/97 dof).\n\nThe spectrum near the maximum count rate\n(measured from T0+0.256 to T0+8.448 s)\nis best fit in the 20 keV - 10 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith alpha = -0.75(-0.08,+0.08)\nand Ep = 314(-17,+19) keV (chi2 = 122/88 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < -3.0\n(chi2 = 122/87 dof).\n\nAll the quoted errors are at the 68% confidence level.\nAll the quoted values are preliminary.",
  "submitter": "Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>"
}