{
  "submittedHow": "web",
  "circularId": 45750,
  "subject": "GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations",
  "eventType": [
    "GRB"
  ],
  "format": "text/plain",
  "createdOn": 1790365684224,
  "body": "Rahul Gupta (NASA GSFC), Peter Veres (UAH), Vikas Chand (LSU), Eric Burns (LSU), Pádraig McDermott (University College Dublin), and L. Scotton (UAH) reports:\n\nWe have estimated the isotropic-equivalent gamma-ray energy of GRB 260924A (The Fermi GBM team, GCN 45712; D'Elia et al., GCN 45713; Salunke et al., GCN 45720; Holzmann Airasca et al., GCN 45721; McDermott et al., GCN 45723; Waratkar et al., GCN 45732; Gupta et al., GCN 45733; and Yu et al., GCN 45741) using the time-integrated Fermi-GBM spectrum and the measured redshift of z = 3.51 (Castro-Tirado et al. GCN 45740). The time-averaged spectrum from T0-11.6 to T0+382.6 s is best fit by a Band function with Epeak = 645 +/- 4 keV, alpha = -0.91 +/- 0.01, and beta = -2.36 +/- 0.01 (McDermott et al., GCN 45723). Using the spectral parameters from McDermott et al., GCN 45723 and measured fluence of 2.84 × 10^-4 erg cm^-2 in the 10-1000 keV observer-frame energy range, and applying a bolometric k-correction to the 1-10,000 keV rest-frame energy range, we obtain an isotropic-equivalent gamma-ray energy of approximately 9.74 × 10^54 erg.\n\nWe adopted a flat Lambda-CDM cosmology with Omega_m = 0.286, Omega_Lambda = 0.714, and H0 = 69.6 km s^-1 Mpc^-1.\n\nThe inferred isotropic-equivalent energy places GRB 260924A among the most energetic gamma-ray bursts known. Its energetics are comparable, within the uncertainties, to those of GRB 221009A, the “BOAT” (Brightest Of All Time).\n\nGiven its extreme energetics and broad observational coverage, continued multi-wavelength observations of GRB 260924A are strongly encouraged.\n",
  "eventId": "GRB 260924A",
  "submitter": "Rahul Gupta at NASA GSFC <rahul.gupta@nasa.gov>"
}