TITLE:   GCN CIRCULAR
NUMBER:  23773
SUBJECT: GRB 190123A: Fermi GBM observation
DATE:    19/01/23 17:30:47 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico & INFN Bari)
reports on behalf of the Fermi GBM Team:


"At 12:19:18.22 UT on 23 January 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190123A (trigger 569938763 / 190123513),
which was also detected by the Swift/BAT (D'Ai et al. 2019, GCN 23769).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 42 degrees.

The GBM light curve consists of a multipeaked emission episode
with a duration (T90) of about 17 s (50-300 keV).
The time-averaged spectrum from T0-5.1 s to T0+10.8 s is
adequately fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.68 +/- 0.25 and
the cutoff energy, parameterized as Epeak, is 310 +/- 100 keV.

The event fluence (10-1000 keV) in this time interval is
(2.07 +/- 0.04)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.1 s in the 10-1000 keV band
is 1.8 +/- 0.2 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."