GCN Circular 23658
Subject
GRB 190109A: Fermi GBM observation
Date
2019-01-09T16:56:02Z (5 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:
"At 05:12:49.45 UT on 09 January 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190109A (trigger 568703574 / 190109217), which was
also detected by the Swift/BAT (Gropp et al. 2019, GCN 23642)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 65 degrees.
The GBM light curve shows a structured emission
with a duration (T90) of about 120 s (50-300 keV).
The time-averaged spectrum from T0-4.096 s to T0+114.690 s is
best fit by a Band function with Epeak = 46.8 +/- 2.2 keV, alpha = 1.3 +/- 0.3,
and beta = -2.71 +/- 0.13
The event fluence (10-1000 keV) in this time interval is
(7.6 +/- 0.4)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+30.91 s in the 10-1000 keV band
is 2.6 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."