[vsnet-grb-info 27379] GRB 210211A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29482
SUBJECT: GRB 210211A: Fermi GBM observation
DATE:    21/02/11 20:30:18 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood at nasa.gov>

J. Wood (NASA/MSFC), A. von Kienlin (MPE), and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 08:43:18.66 UT on 11 February 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 210211A (trigger 634725803 / 210211363)
which was also detected by the Swift/BAT and Swift/XRT (E. Troja et al. 2021, GCN 29472).
The Fermi GBM Final Real-time Localization (GCN 29470) is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 50.5 degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 29 s (50-300 keV).
The time-averaged spectrum from T0-4 s to T0+27 s is
best fit by a Band function with Epeak = 95 +/- 35 keV,
alpha = 2.8 +/- 3.1, and beta = -1.5 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(3.1 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.8 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:
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/"