{
  "subject": "GRB 240118C: Fermi GBM Observation",
  "createdOn": 1705712516022,
  "circularId": 35586,
  "submittedHow": "web",
  "body": "V. Sharma (NASA-GSFC/UMBC) and C. Meegan (UAH) report on behalf of the \nFermi Gamma-ray Burst Monitor Team:\n\n\"At 17:23:23.93 UT on 18 January 2024, the Fermi Gamma-ray Burst Monitor (GBM) \ntriggered and located GRB 240118C (trigger 727291408/240118725), which was also \ndetected by Swift/BAT-GUANO (DeLaunay et al. 2024, GCN 35581).\nThe Fermi Final Real-time Localization is reported in GCN 35576.\n\nThe angle from the Fermi LAT boresight is 90 degrees.\n\nThe GBM light curve consists of multiple pulses with a duration (T90)\nof about 31 s (50-300 keV). The time-averaged spectrum from \nT0-0.6 to T0+32.5 s is best fit by a power law function with \nan exponential high-energy cutoff.\nThe power law index is -1.39 +/- 0.03 and the cutoff energy,\nparameterized as Epeak, is 144 +/- 10 keV.\n\nThe event fluence (10-1000 keV) in this time interval is (1.23 +/- 0.04)E-05 erg/cm^2. \nThe 1-sec peak photon flux measured starting from T0+29.7 s in the 10-1000 keV band \nis 13.6 +/- 0.5 ph/s/cm^2.\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/.\"",
  "submitter": "Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov>",
  "eventId": "GRB 240118C",
  "bibcode": "2024GCN.35586....1S"
}