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GCN Circular 33343

Subject
GRB 230217A: AGILE/MCAL detection
Date
2023-02-18T10:41:34Z (2 years ago)
From
Claudio Casentini at INAF-IAPS <claudio.casentini@inaf.it>
C. Casentini (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), F. Longo
(Uni. Trieste, INFN Trieste) M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), C. Pittori, F. Lucarelli,
A. Argan, M. Cardillo, Y. Evangelista, L. Foffano, G. Piano
(INAF/IAPS), A. Addis, L. Baroncelli, A. Bulgarelli, A. Di Piano,
V. Fioretti, G. Panebianco, N. Parmiggiani (INAF/OAS-Bologna), M. Romani
(INAF/OA-Brera), M. Marisaldi (INAF/OAS-Bologna, Bergen University),
M. Pilia, A. Trois (INAF/OA Cagliari), I. Donnarumma, E. Menegoni,
A.Ursi (ASI), A. Giuliani (INAF/IASF-Mi) and P. Tempesta (TeleSpazio),
report on behalf of the AGILE Team:

The AGILE satellite detected the short GRB 230217A at
T0 = 2023-02-17 21:53:10.87 (UTC), reported by Fermi/GBM (GCN #33338Loading...
 
 ) and
Swift BAT (GCN #33339Loading...
 
 ).

The burst is clearly visible in the AGILE scientific ratemeters of the
MiniCALorimeter (MCAL; 0.4-100 MeV), and in all the panels of the
AntiCoincidence detectors (AC Top, 50-200 keV; AC Lat, 80-200 keV).
The event lasted about 2 s and it released a total number of 7554 counts
in the MCAL detector (above a background rate of 529 Hz), and 38605 counts
in the AC Top detector (above a background rate of 3530 Hz).
The AGILE ratemeters light curves can be found at:
http://www.agilescienceapp.it/notices/GRB230217A_AGILE_RM_ND.png .

The event also triggered a high-time resolution MCAL data acquisition,
from T0-0.7 s to T0+5.8 s (UTC), and released 2515 counts in the detector,
above a background rate of 776 Hz. The MCAL light curve can be found at:
http://www.agilescienceapp.it/notices/GRB230217A_082311_603755590.000000.png
.

The time-integrated spectrum of the burst between T0-1s and T0+1s, fitted
in the energy range 0.4-10 MeV with a p.l. with ph. ind. = -2.12 (+/-0.08)
resulting in a reduced chi-squared of 0.92 (48 d.o.f.)
and a fluence of 4.05e-06 ergs/cm^2 (90% confidence level),
in the same energy range.

At the T0, the event was 59 deg off-axis.
Additional analysis of AGILE data is in progress.
Automatic MCAL GRB alert Notices can be found at:
https://gcn.gsfc.nasa.gov/agile_mcal.html