{
  "format": "text/plain",
  "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 260601B\n(GECAM-B detection: Yu et al., GCN 44767; Wang et al., GCN 44768;\nNuSTAR detection: Waratkar et al., GCN 44771;\nCALET-GBM detection: Sugita et al., GCN 44773;\nInsight-HXMT detection: Wang et al., GCN 44785;\nGlowbug detection: Cheung et al., GCN 44801)\ntriggered Konus-Wind at T0=69173.304 s UT (19:12:53.304).\n\nThe burst light curve shows a multipeaked structure\nwhich starts at ~T0-3.2 s and has a total duration of ~230 s.\nThe emission is seen up to ~8 MeV.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB260601_T69173/\n\nAs observed by Konus-Wind, the burst\nhad the total fluence of 3.34(-0.17,+0.17)x10^-4 erg/cm2,\nand the 64-ms peak flux, measured from T0+27.552 s,\nof 1.66(-0.19,+0.19)x10^-5 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+210.688 s)\nis best fit in the 20 keV - 10 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.79(-0.10,+0.12),\nthe high energy photon index beta = -1.74(-0.05,+0.04),\nthe peak energy Ep = 441(-68,+82) keV\n(chi2 = 125/97 dof).\n\nThe 'peak-flux' spectrum \n(measured from T0+24.832 to T0+31.232 s)\nis best fit in the 20 keV - 10 MeV range\nby the GRB (Band) model with the following parameters:\nthe low-energy photon index alpha = -0.89(-0.07,+0.07),\nthe high energy photon index beta = -1.82(-0.06,+0.05),\nthe peak energy Ep = 671(-98,+117) keV\n(chi2 = 108/82 dof).\n\nAssuming a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,\nand Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimated the burst\nisotropic energy release E_iso, the isotropic peak luminosity L_iso, and\nthe rest-frame peak spectral energy Ep,z of the burst at different redshifts.\nWith the obtained estimates GRB 260601B is consistent with the 68% prediction band\nof the 'Amati' relation for z >~0.2 and with the 68% prediction band of the 'Yonetoku' relation\nfor z>~1.0 (see http://www.ioffe.ru/LEA/GRBs/GRB260601_T69173/GRB260601B_rest_frame.pdf)\n\nAll the quoted errors are at the 68% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 44806,
  "eventId": "GRB 260601B",
  "createdOn": 1780503285152,
  "submittedHow": "web",
  "submitter": "Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>",
  "subject": "Konus-Wind detection of GRB 260601B/EP260601a"
}