[vsnet-grb-info 5806] GRB 080319C: AGILE-MCAL observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7457
SUBJECT: GRB 080319C: AGILE-MCAL observation of the prompt emission
DATE:    08/03/19 19:09:02 GMT
FROM:    Sandro Mereghetti at IASF/CNR  <sandro at iasf-milano.inaf.it>

M. Marisaldi (INAF/IASF Bologna), F. Fornari (INAF/IASF Milano), C. 
Labanti, F. Fuschino, M. Galli, A. Bulgarelli, F. Gianotti, M. Trifoglio, 
G. Di Cocco (INAF/IASF Bologna), E. Costa, E. Del Monte, I. Donnarumma, Y. 
Evangelista, M. Feroci, I. Lapshov, F. Lazzarotto, L. Pacciani, M. 
Rapisarda, P. Soffitta (INAF/IASF Roma), A. Giuliani, S. Vercellone, A. 
Chen, S. Mereghetti, A. Pellizzoni, F. Perotti, M. Fiorini, P. Caraveo 
(INAF/IASF Milano), M. Tavani, G. Pucella, F. D'Ammando, V. Vittorini, A. 
Argan, A. Trois (INAF/IASF Rome), G. Barbiellini, F. Longo, E. Vallazza 
(INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2), M. Prest 
(Universita` dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1), and P. 
Giommi, C. Pittori, (ASDC) and L. Salotti (ASI), on behalf of the AGILE 
Team, report:

"The Swift localized GRB 080319C (Pagani et al., GCN 7442) triggered the 
Mini-Calorimeter (MCAL) instrument onboard the AGILE satellite at 12:25:56 
UT (=T0). The MCAL instrument covers the energy range 350 keV - 10 MeV, 
without imaging capabilities.

The MCAL light curve shows two main overlapping broad peaks, the first 
peaking at T0 and the second peaking at T0+9s in the 350-700 keV energy 
band. Above 700 keV only the first peak is still detected, with 5 sigma 
detection also in the 1.4-2.8 MeV energy band. Using the preliminary 
in-flight calibration, we can estimate the 1-s peak flux in the 350-700 
keV energy band at T0 to be 2.0(-0.8,+0.9) photons/cm2/s.

The Swift localization is out of the field of view of the AGILE Gamma-Ray 
Imaging Detector (GRID), sensitive in the 50 MeV - 50 GeV energy range. 
Analysis of the GRID count rate does not show any detection. The event was 
well outside of the SuperAGILE field of view as well, but the event passed 
through the collimator shield and was weakly detected in the count rate."

We incidentally note that the brighter GRB 080319B (Racusin et al. GCN 
7427) was not observed by the AGILE instruments due to Earth occultation.

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