[vsnet-grb-info 28430] GRB 210727A: AGILE/MCAL detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30533
SUBJECT: GRB 210727A: AGILE/MCAL detection
DATE:    21/07/27 14:43:39 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi at gmail.com>

A. Ursi (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M. Pilia
(INAF/OA-Cagliari), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A.
Argan, M. Cardillo, C. Casentini, Y. Evangelista, G. Piano, A. Ursi
(INAF/IAPS), F. Lucarelli, C. Pittori (SSDC, and INAF/OAR), A. Bulgarelli,
V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), 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 the short GRB 210727A (Fermi
trigger no. 649072251) at T0 = 2021-07-27 09:50:47.40 +/- 0.01 s (UTC).

The event lasted about 1.5 s and released a total number of ~1300 counts in
the detector (in the 0.4-100 MeV energy range), above an average background
rate of 560 Hz. The MCAL light curve can be found at
http://www.agilescienceapp.it/notices/074097_GRB_MCAL_554464247.402495.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. = -1.59 -/+ 0.07, resulting
in a reduced chi-squared of 1.23 (62 d.o.f.) and a fluence of 9.6e-06
ergs/cm^2 (90% confidence level), in the same energy range.

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.