{
  "submitter": "Lorenzo Scotton at UAH <lscottongcn@outlook.com>",
  "eventId": "GRB 240123B",
  "submittedHow": "web",
  "circularId": 35632,
  "body": "L. Scotton (UAH) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 17:48:03.22 UT on 23 January 2024, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 240123B (trigger 727724888/240123742).\nwhich was also detected by Swift/BAT-GUANO (Ronchini et al. 2024, GCN 35629).\nThe Fermi GBM Final Real-time Localization was reported in GCN 35608.\n\nThe angle from the Fermi LAT boresight is 51 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 12 s (50-300 keV). The time-averaged spectrum\nfrom T0-0.5 to T0+11.5 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -0.6 +/- 0.2 and the cutoff energy,\nparameterized as Epeak, is 250 +/- 30 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(2.6 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+4.9 s in the 10-1000 keV band is 2.4 +/- 0.2 ph/s/cm^2.\n\nA Band function fits the spectrum equally well\nwith Epeak= 130 +/- 30 keV, alpha = 0.1 +/- 0.4 and beta = -1.9 +/- 0.1.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog:\nhttps://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n\nFor Fermi GBM data and info, please visit the official Fermi GBM Support Page:\nhttps://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "createdOn": 1706211945633,
  "subject": "GRB 240123B: Fermi GBM Observation",
  "bibcode": "2024GCN.35632....1S"
}