[vsnet-grb-info 21822] GRB 190220B: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23921
SUBJECT: GRB 190220B: Fermi GBM observation
DATE:    19/02/21 19:49:45 GMT
FROM:    Cori Fletcher at USRA/NASA  <corinne.l.fletcher at nasa.gov>

C. Fletcher (USRA) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 20:15:31.49 UT on 20 February 2019, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 190220B (trigger 572386536 / 190220844).

which was also detected by INTEGRAL (Gotz et al. 2019, GCN 23915).
The GBM on-ground location is consistent with the INTEGRAL position.

The angle from the Fermi LAT boresight at the GBM trigger time is 23 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 109 s (50-300 keV).
The time-averaged spectrum from T0-51.201 s to T0+59.393 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.4 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 83 +/- 8 keV

The event fluence (10-1000 keV) in this time interval is
(7.2 +/- 0.6)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+38.72 s in the 10-1000 keV band
is 2.5 +/- 0.2 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 73 +/- 13 keV, alpha = -1.3 +/- 0.2 and beta = -2.5 +/- 0.4.


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