TITLE: GCN CIRCULAR NUMBER: 17627 SUBJECT: GRB150323C: Fermi GBM detection DATE: 15/03/24 00:25:37 GMT FROM: Matthew Stanbro at UAH/Fermi Matthew Stanbro (UAH) reports on behalf of the Fermi GBM Team: "At 17:05:09.64 UT on 23 March 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150323C (trigger 448823112 / 150323712) which was also detected by the Swift/BAT (Amaral-Rogers et al. 2015, GCN 17621) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 58 degrees. The GBM light curve consists of several episodes with a duration (T90) of about 43 s (50-300 keV). The time-averaged spectrum from T0-10.24 s to T0+30.72 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.15 +/- 0.16 and the cutoff energy, parameterized as Epeak, is 107 +/- 18 keV. The event fluence (10-1000 keV) in this time interval is (2.50 +/- 0.19)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-1.22 s in the 8-1000 keV band is 1.64 +/- 0.20 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."