[vsnet-grb-info 6237] GRB 080607: AGILE-MCAL observation of the prompt emission

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7866
SUBJECT: GRB 080607: AGILE-MCAL observation of the prompt emission
DATE:    08/06/09 15:44:57 GMT
FROM:    Marco Feroci at IASF/INAF  <feroci at iasf-roma.inaf.it>

M. Marisaldi, F. Fuschino, M. Galli, C. Labanti, 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), F. 
Fornari, 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 080607 (Mangano et al., GCN 7847; Stamatikos et 
al., GCN 7852) triggered the Mini-Calorimeter (MCAL) instrument onboard 
the AGILE satellite at 06:07:23 UT (=T0). The MCAL instrument covers the 
energy range 350 keV - 10 MeV, without imaging capabilities.

Using the preliminary in-flight calibration and assuming a Crab-like 
spectrum, we can estimate the fluence in the 350-700 keV energy band to be 
(23 +/- 7) photons/cm2 corresponding to (1.8 +/- 0.5)x10^-5 erg/cm2, in 
the time interval T0-T0+14 s. The 1-s peak flux measured at T0+5.1 s is 
(4.2 +/- 1.2) photons/cm2/s in the same energy band. The GRB was detected 
also in the 1.4-2.8 MeV energy band with a 10 sigma significance in the 
256-ms time window. 

We note that the quoted fluence is in agreement within errors with that 
obtained using the Konus-Wind spectrum reported in Golenetskii et al., GCN 
7862. Assuming the spectral model reported in GCN 7862, an agreement in 
flux within 10% for the energy band 350-700 keV is obtained.

The Swift localization is at about 113 degrees off-axis with respect to 
the AGILE pointing, so well 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. 

This GRB triggered also SuperAGILE and was detected at about 17 sigma 
significance level in the 18-60 keV band, although it was well outside the 
field of view, and was detected through the collimator shielding." 

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