GRB 220525A: Fermi GBM Detection

"At 00:10:54 UT on 25 May 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220525A (trigger 675130259/220525008) which was also detected by Konus-Wind (D. Frederiks et al. 2022, GCN 32122) and CALET (Y. Kawakubo et al. 2022, GCN 32125) and localized by IPN (Kozyrev et al. 2022, GCN 32118). The Fermi GBM Final Real-time Localization (GCN 32112) is consistent with the IPN triangulation. The angle from the Fermi LAT boresight is 58 degrees. The GBM light curve shows a single bright emission episode with a duration (T90) of about 16.1 s (10-1000 keV). The time-averaged spectrum from T0-10 to T0+15 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.12 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 176 +/- 10 keV. The event fluence (10-1000 keV) in this time interval is (1.45 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.7 s in the 10-1000 keV band is 15.4 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog:https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page:https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"