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GCN Circular 28829

Subject
GRB 201104A: AGILE/MCAL detection
Date
2020-11-04T20:46:45Z (4 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), F. Verrecchia, C. Pittori (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C.
Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (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 201104A at T0 = 2020-11-04
00:00:56.77 +/- 0.01 s (UTC), reported by Fermi/GBM (GCN #28823Loading...
 
 ) and
INTEGRAL/SPI-ACS (trigger ID 8789,0).

The event lasted about 8 s and released a total number of ~7200 counts in
the detector (in the 0.4-100 MeV energy range), above an average background
rate of 640 Hz.

The light curve shows sveral episodes and can be found at
http://www.agilescienceapp.it/notices/GRB_070287_531532856.770000.png .

The time-integrated spectrum of the burst can be fitted in the energy range
0.4-20 MeV with a single power-law with ph.ind. = -2.26 -0.15/+0.18,
resulting in a reduced chi-squared of 1.06 (75 d.o.f.) and a fluence of
3.57e-06 ergs/cm^2 (90% confidence level), in the same energy range.

The burst is clearly visible in the AGILE scientific ratemeters of the MCAL
detector. The event released a total number of 25100 counts, above a
background rate of 1255 Hz. The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/GRB_201104A_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.
Automatic MCAL GRB alert Notices can be found at:
https://gcn.gsfc.nasa.gov/agile_mcal.html.

[GCN OPS NOTE(06Nov20): Due to the uncertainty of the arrival time with respect 
to the downtime window (15 hours) of the GCN Circulars processing system, 
the error in the date-time in the header of this Circular can be off anywhere from 0-15 hours.]