TITLE: GCN CIRCULAR NUMBER: 19587 SUBJECT: GRB 160625B: Fermi GBM refined analysis DATE: 16/06/26 08:01:15 GMT FROM: Eric Burns at U of Alabama E. Burns (UAH) reports on behalf of the Fermi GBM Team: "We report temporal and spectral analysis on GRB 160625B, covering all three Fermi trigger times (LAT trigger 488587408 / 160625947 GBM triggers 488587220 / 160625945 and 488587880 / 160625952). All times are relative to the first GBM trigger time. The GBM light curve consists of multiple peaks with a total duration (T90) of about 460 s (50-300 keV). The 1.024-sec peak photon flux of the main peak measured starting from T0+188.707 s in the 10-1000 keV band is 167 +/- 1 ph/s/cm^2. The soft peak that initially triggered GBM is about 1 second long. The time-averaged spectrum from T0+0.002 s to T0+1.056 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.2 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 68 +/- 1 keV. The event fluence (10-1000 keV) in this time interval is (1.65 +/- 0.03)E-06 erg/cm^2. The main peak that triggered the LAT is about 25 seconds long. The time-averaged spectrum from T0+187.427 s to T0+212.003 s is well fit by a Band function with Epeak = 657 +/- 5 keV, alpha = -0.74 +/- 0.00, and beta = 2.36 +/- 0.01. The event fluence (10-1000 keV) in this time interval is (5.00 +/- 0.01)E-04 erg/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."