GCN Circular 27155
Subject
GRB 200219C: Fermi GBM detection
Date
2020-02-20T17:06:32Z (4 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
R. Hamburg (UAH), C. Meegan (UAH) and E. Bissaldi (Politecnico and INFN
Bari)
report on behalf of the Fermi GBM Team:
"At 23:57:10.33 UT on 19 February 2020, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 200219C (trigger 603849435 / 200219998), which was
also detected by Fermi-LAT (Dirirsa et al. 2020, GCN 27151). The Fermi GBM
Final Real-time Localization (GCN 27145) is consistent with the LAT
position.
The GBM light curve shows a bright main peak followed by a weaker emission
episode and has a duration (T90) of about 22 s (50-300 keV).
The time-averaged spectrum from T0-0.00 s to T0+25.9 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.09 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 199 +/- 9 keV.
A Band function fits the spectrum equally well with
Epeak = 181 +/- 12 keV, alpha = -1.05 +/- 0.03 and beta = -2.50 +/- 0.24.
The event fluence (10-1000 keV) in this time interval is
(1.87 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.7 s in the 10-1000 keV band
is 24.8 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support
Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"