GCN Circular 34237

G. Panebianco (Univ. Bologna - INAF/OAS Bologna), C. Casentini (INAF/IAPS), F. Verrecchia,
C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
A. Ursi (ASI and INAF/IAPS), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano,
G. Piano (INAF/IAPS), A. Addis, L. Baroncelli, A. Bulgarelli, A. Ciabattoni,
A. Di Piano, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna),
F. Lucarelli (SSDC, and INAF/OAR), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari), F. Longo (Univ. Trieste and INFN Trieste),
I. Donnarumma, E. Menegoni (ASI), A. Giuliani (INAF/IASF-Mi),  P. Cattaneo (INFN Pavia),
F. Cutrona (Univ. Milano Bicocca) and P. Tempesta (TeleSpazio)
report on behalf of the AGILE Team:

The AGILE satellite detected the GRB 230723A at T0 = 2023-07-23 04:38:43 s (UTC),
reported by Fermi GBM and Global MASTER-Net (GCNs #34232
Not found
 
 
, #34233
Not found
 
 
).

The burst is clearly visible in the AGILE scientific ratemeters of the
MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors.
The event lasted about 4 s and it released a total number
of 3239 counts in the MCAL detector (above a background rate of 499 Hz)
and 16051 counts in the AC-Top detector (above a background rate of 2505 Hz).

The AGILE ratemeters light curves can be found at
http://www.agilescienceapp.it/notices/GRB230723A_AGILE_RM_ND.png .

The event also triggered a high time resolution MCAL data acquisition,
from T0-5.0 s to T0+8.6 s (UTC), and released 1186 counts in the detector, above
a background rate of 449 Hz.

The MCAL light curve can be found
at http://www.agilescienceapp.it/notices/GRB230723A_084565_617171923.000000.png .

The time-integrated spectrum of the burst between T0 and T0+2s be fitted in the
energy range 0.4-10 MeV with a power-law with ph. ind. = -1.8 +/- 0.3,
resulting in a reduced chi-squared of 0.94 (48 d.o.f.) and a fluence of 2.5e-06
ergs/cm^2 (90% confidence level), in the same energy range.

At the T0, the event was 103 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