[vsnet-grb-info 25709] GRB 200524A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27809
SUBJECT: GRB 200524A: Fermi GBM detection
DATE:    20/05/25 00:03:51 GMT
FROM:    Stephen Lesage at Fermi-GBM Team  <sjl0014 at uah.edu>

S. Pookalil (UAH), B. Mailyan (Institute for Basic Science, South Korea),
and R. Hamburg (UAH)
report on behalf of the Fermi GBM Team:

"At 05:04:00.36 UT on 24 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 200524A (trigger 611989445 / GBM200524211),
which was also detected by the Fermi/LAT (Dirirsa et al. 2020, GCN 27797)
The Fermi GBM Final Real-time Localization is consistent with the LAT
position.
Swift has initiated a ToO observation of this burst (GCN 27798).

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

The GBM light curve shows a multi-peaked structure
with a duration (T90) of about 38 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+25.1 s is
best fit by a Band function with Epeak = 192 +/- 16 keV,
alpha = -0.66 +/- 0.06, and beta = -1.77 +/- 0.03

The event fluence (10-1000 keV) in this time interval is
(2.08 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+5.3 s in the 10-1000 keV band
is 13.3 +/- 0.3 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/"