[vsnet-grb-info 27286] GRB 210202A: AGILE/MCAL detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29389
SUBJECT: GRB 210202A: AGILE/MCAL detection
DATE:    21/02/03 18:36:16 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi at gmail.com>

A. Ursi, M. Cardillo (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, C. Casentini, Y.
Evangelista, G. Piano (INAF/IAPS), F. Lucarelli, F. Verrecchia (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ.
Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of
the AGILE Team:

The AGILE Mini-CALorimeter (MCAL) detected GRB 210202A at T0 = 2021-02-02
20:10:32.98 +/- 0.01 s (UTC), reported by Fermi/GBM (GCN #29380, #29387)
and Fermi/LAT (GCN #29386).

The event lasted about 2.5 s and released a total number of ~2000 counts in
the detector (in the 0.4-100 MeV energy range), above an average background
rate of 570 Hz.

The light curve shows a single peak and can be found at
http://www.agilescienceapp.it/notices/GRB210202A_AGILE_MCAL.png .

The time-integrated spectrum of the burst can be fitted in the energy range
0.4-10 MeV with a single power-law with ph.ind. = -3.01 -0.52/+0.84,
resulting in a reduced chi-squared of 0.90 (48 d.o.f.) and a fluence of
2.8e-06 ergs/cm^2 (90% confidence level), in the same energy range.

The event is also clearly visible in the scientific ratemeters of the
SuperAGILE (SA; 18-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and
AntiCoincidence (AC; 50-200 keV) detectors. The burst released 340 counts
in the SA detector (above a background rate of 100 Hz), 4580 counts in the
MCAL detector (above a background rate of 1260 Hz), and 12340 counts in the
AC detector (above a background rate of 3700 Hz). The AGILE ratemeters
light curves can be found at:
http://www.agilescienceapp.it/notices/GRB210202A_AGILE_RM.png .

The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the
energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress.
This GRB event did not generate an automatic alert notice. Automatic MCAL
GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html
.