[vsnet-grb-info 21711] GRB 190129A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23810
SUBJECT: GRB 190129A: Fermi GBM detection
DATE:    19/01/29 21:36:58 GMT
FROM:    Bagrat Mailyan at UAH  <bm0054 at uah.edu>

E. Bissaldi (Politecnico & INFN Bari), B. Mailyan (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 12:21:41.87 UT on 29 January 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190129A (trigger 570457306 / 190129515),
which was also detected by MAXI/GSC (Nakahira et al. 2019, GCN 23806).
The GBM on-ground location is consistent with the MAXI/GSC position.

The angle from the Fermi LAT boresight at the GBM trigger time is 118
degrees.

The GBM light curve shows/consists of a single peak
with a duration (T90) of about 8.7 s (50-300 keV).
The time-averaged spectrum from T0-1 s to T0+4 s is
adequately fit by
a power law function with an exponential
high-energy cutoff.  The power law index is -1.37 +/- 0.23  and
the cutoff energy, parameterized as Epeak, is 78 +/- 19 keV.

The event fluence (10-1000 keV) in this time interval is
(9 +/- 1)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.38 s in the 10-1000 keV band
is 3.7 +/- 0.3 ph/s/cm^2.

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